Hello! magazine readers may know Winkleman, 45, from her appearances at the likes of Royal Ascot and Trooping the Colour, but far more recognise her for her 23-year acting career, starring in everything from the hugely popular US sitcom Two and a Half Men to her most legendary role as Big Suze, the “mental posho” in the cult Peep Show with David Mitchell and Robert Webb.

“I just think, ‘Shut up. You’re not allowed to complain about anything. You’re so lucky’”

DAN KENNEDY FOR THE TIMES MAGAZINE. DRESS, REISS.COM. SHOES, MALONESOULIERS.COM. EARRINGS, BEARBROOKSBANK.COM

When — occasionally — her two worlds collide, such as when she appeared at the late Queen’s Diamond Jubilee celebrations, there’s internet meltdown. That same year, having spotted Winkleman at the Queen’s lying in state, Times columnist Caitlin Moran tweeted, “Just watched Prince Charles stand vigil over his dead mother whilst Big Suze from Peep Show looked on. There’s no point in even saying, ‘This country is nuts,’ any more.”

Winkleman is oblivious to such (affectionate) commentary because, most unusually for an actor, she has no social media. As a vocal campaigner for limiting smartphone and “ed tech” (educational technology) for children, she realises this could be a problem. “It’s a fine balance,” she says. “I have to walk the walk [of showing life’s possible without social media], but at the same time, with it I would be able to spread my message like wildfire. So it’s probably slightly masochistic and thick of me to be without it.”

• Sophie Winkleman: Schools gave my kids screens — so I pulled them out

Tall (5ft 10in), charismatic and smart, Winkleman is sitting in a hotel bar in east London. As soon as she enters she tells me she “looks awful” (she doesn’t), and frequently halts the conversation to tell me she’s “boring” (she isn’t). After the subsequent photoshoot, she messages to tell me how “ungainly and hunched” she is (she’s not).

As the interview draws to a close she laughs as she reveals how much she “needs a fag. I promise I only smoke about three a week; I reckon that’s only as bad as standing behind a car.” How about vaping? “No way. I disapprove of Febreze smoking — vapes leave that cloud of watermelon goop in your face. Revolting. I love smoking, but it’s a major flaw. Everyone in my generation has managed to stop. I’m sorry, I know how thick it is.”

The continuous self-deprecation is a quality she shares with her half-sister Claudia Winkleman (their father is the publisher Barry Winkleman), although the pair have an eight-year age gap and grew up in separate houses. “She and Tess [Daly] have done so well on Strictly and now The Traitors is going brilliantly. It’s all very exciting,” she says.

In the new BBC drama Wild Cherry

BBC

In fact, the Winkleman siblings are on the verge of taking over the BBC, with Claudia tipped for a new chat show and Sophie now starring in the hot autumn drama Wild Cherry. The glossy story of a group of parents and daughters who attend the same private girls’ school, it’s very much in the Big Little Lies mode, packed with buried secrets, betrayals and fraught mother-daughter relationships. There’s also top kitchen porn and — no spoilers — a strong plotline about the dangers posed by social media.

It’s disturbing viewing for any mother of teenage girls. Winkleman has two daughters: Maud, 12, and Isabella, 9. She could use the drama as a propaganda video for her campaigning. “I totally agree. So many teenagers are going through hell at the moment because of grown-ups being morons and not banning all this crap. It’s perfect timing, because everything’s heating up on that front. We saw [Netflix’s] Adolescence have a big impact. So maybe now this? I’m quite sad it takes a work of fiction to make people start listening. It’s really quite depressing when all the doctors and teachers are telling politicians what social media is doing to children. But maybe a drama will make them sit up and do something.”

Message aside, for Winkleman it was a hoot to play her character, Frances, “who’s a real Hyacinth Bucket, a curtain twitcher”. Having recently made a couple of costume dramas — ITV’s Sanditon and Julian Fellowes’ Belgravia: the Next Chapter — “suddenly being in something so modern and shocking was really fun. My parts before were quite proper and polite, so to be a nightmare again was really enjoyable.”

With Paterson Joseph and Robert Webb in Peep Show

CHANNEL 4

Winkleman, whose mother is the children’s author Cindy Black, grew up in Primrose Hill, north London. “Today it’s all Space NKs, but back then it was full of lentil shops,” she says. She attended the private City of London School for Girls and, like some characters in Wild Cherry, found herself bullied. “I loved my teachers a lot, but I had a bad time with a group of girls. I really believe if social media had existed then I’d have been in big trouble, because then you could go home and be safe. Now the classroom is 24/7.”

She read English at Cambridge, where she joined Footlights. After graduating she worked nonstop on stage and in film, including starring as the older Susan in the 2005 film The Chronicles of Narnia. She then landed the Big Suze gig, appearing on and off in Robert Webb and David Mitchell’s Peep Show for five years.

That show’s many fans happened to include Lord Frederick Windsor, whom she met in Soho on New Year’s Eve in 2007, when both were leaving separate parties and went for the same taxi. His first words to her were, “You’re Big Suze. I love you!” As she told me previously, she wasn’t from a family that aspired to her bagging a royal, her paternal grandfather having been a Marxist, “and I think Freddie could probably sense that”.

Two years later, the couple married at the Chapel Royal at Hampton Court Palace, where the 400 guests included Princess Eugenie and the rock star Bryan Adams, who performed his song Heaven at the reception. Winkleman is very funny about how her lack of “bridezilla” instincts, plus being more focused on an upcoming move to Los Angeles for work, meant she willingly left the organisation of the entire affair to her mother-in-law, Princess Michael (sometimes unkindly nicknamed Princess Pushy). “I didn’t know anyone at my wedding,” she tells me. “I had my best pals there, but basically it was full of faces I’d never seen before.”

Her wedding to Lord Frederick Windsor in 2009. Princess Michael chose her dress: “Very sweet and puffy but I looked barking”

GETTY IMAGES

Princess Michael — who, says her daughter-in-law, did a “brilliant” job — even chose her dress by Anna Bystrova for Roza Couture (“very sweet and puffy, but I looked barking”), Winkleman later recalled. She hadn’t bothered to work out a hairstyle and the end result, she claims, was “disgusting. Freddie still gets upset about it.”

The very next morning, the newlyweds forsook a honeymoon and decamped to Los Angeles for the following seven years. They “utterly loved” no one knowing their royal connections. Frederick worked at JPMorganChase (he’s now based in the company’s London office) and played football with a bunch of expats every weekend. Winkleman was cast as Ashton Kutcher’s girlfriend, Zoey, in Two and a Half Men (it’s shown here on ITVX), and wrote (unused) screenplays for the likes of Penélope Cruz and Salma Hayek. “I loved parts of the American DNA, the dynamism and can-do positivity. They’re happy for their friends when they do well. The flipside is they worship money and fame a bit too much.”

• Sophie Winkleman: I didn’t know anyone at my royal wedding

After Maud was born in 2013, the couple made the tough decision to return to London to be nearer their families, settling in Battersea — “It’s adorable, but it’s not near any Tube stations or many good schools, so I don’t know if we’d choose it again.”

Winkleman has always been endearingly frank about finding motherhood challenging. She says she loved making three seasons of Sanditon, Andrew Davies’ take on Jane Austen’s unfinished novel, because — cast, script and director aside — “I had a clean, empty, silent flat to myself in Bristol for filming and everything at home was Freddie’s problem.” Childcare is a perpetual issue, as she’s either unemployed with no need of help or she’s flat-out unavailable. “Then when you do get a job, you suddenly go into cafés and say, ‘Do you like children? If so, for the next four months, just come to my house.’ I find anyone and everyone. The poor kids have different people almost every day.”

Her parents, who live nearby, help out a lot. “We rely on them so much. I’m very strict with them. They’re not allowed to get ill; they have to eat just kale and beetroot for the rest of their lives.” When it comes to disciplining the children, she says, “My mum despairs of me. She says, ‘You preach all this crap and look at your own kids.’ ”

Opposite Ashton Kutcher in Two and a Half Men, 2003

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One example is that Maud now owns a smartphone. “She went to a school where most had one and said, ‘OK, enough already. Your ideology is really destroying my life. It’s just agony.’ So I paid far too much to some guy to make her smartphone safe. It’s not remotely safe. She doesn’t have social media, but it’s an Apple phone so she can be the same as her friends and it still kills me. So I failed with her and I’ll probably fail with the young one too, as they rule the roost, but I’m never going to stop fighting.”

• School heads call for blanket ban on smartphones

Even more than smartphones, her bugbear is ed tech, increasingly employed by schools to encourage children to learn everything from spellings to times tables via supposedly “fun” apps and computer programs. An exasperated Winkleman previously pulled her daughters out of two schools that were giving iPads to children from the age of five. She’s impressively versed in evidence that typing and reading from a screen do not implant information into the brain as effectively as handwriting and turning pages in a book.

“Silicon Valley guys send their children to schools where the tech use is unbelievably moderate because they know how addictive this stuff is, and yet we’re lapping it all up like idiots. It’s absolute junk but it looks progressive and shiny, so billions are being invested into it that should go into having more teachers in state schools, with higher salaries. I don’t understand why decision-makers don’t talk to teachers, who see how rubbish this all is. Or to doctors — they are seeing so many bad effects from too much screen use: eyesight issues, hormone disruption, sleep imbalance, posture deformation.”

She has organised several events on the subject (she’s planning another in parliament later this month), where she’s spoken eloquently alongside the likes of Jonathan Haidt, the psychologist and author of The Anxious Generation, who argues that screens have caused an “epidemic of mental illness” in children and “rewired” their brains, resulting in “attention fragmentation”; and the actor Hugh Grant, a father of five. Another ally is Katharine Birbalsingh, the head of Michaela Community School in Wembley, north London, who’s regularly clobbered on social media for running “Britain’s strictest school”.

“I don’t understand the viciousness that woman receives,” Winkleman says. “The parents and the children love her. They’re all incredibly polite. They want to learn.”

It’s the same with Jamie Oliver, a close friend and Isabella’s godfather, who made Winkleman’s 40th birthday cake, consisting of 20 layers of cheap chocolate she loves (“the naffest things — Twixes and Reese’s Peanut Butter Cups”). “Jamie’s trying to do something good. It’s another weird British thing: if someone tries to put themselves above the parapet, people hurl rocks at them. He could just be a loaded chef and [Birbalsingh] could be in charge of the best school in Britain, but instead they try to change lives.”

With Prince Edward, Princess Anne and Prince Harry at the wedding of Lady Gabriella Windsor, 2019

GETTY IMAGES

She sees the same negativity directed at her in-laws. “The senior royals work really hard with thousands of charities in Britain and around the world, behind the scenes as well as front-facing. There’s no getting away from the fact they add huge prestige and heft to whatever cause they’re supporting. The King’s Trust is the greatest engineer for social mobility in Britain. Princess Anne does nearly 500 engagements per year. The Duchess of Edinburgh has just come back from Sudan, meeting surgeons who operate on violently raped toddlers — that is traumatic, serious work. I truly think my communist grandfather would be convinced by my arguments in favour of the royal family.”

Gilded as their lives may appear, Winkleman and her husband have had their share of pain. Last year Thomas Kingston, the husband of Frederick’s sister, Lady Gabriella Kingston, to whom the couple are extremely close, died by suicide. “That was a big tragedy in our lives and we all miss him every day. My girls adored him. It’s brutal. We’re still in touch with all his family and it feels like he’s still with us.”

Frederick has since started working with a charity, James’ Place, which helps men with suicidal thoughts. “It’s not a positive to come out of it at all, but it makes you so much more aware that the exterior of someone can be very different from what’s going on inside.”

“I really thought I was going to croak. I prayed: make Freddie meet someone nice”

DAN KENNEDY FOR THE TIMES MAGAZINE. DRESS: REISS.COM

As for Winkleman, after Isabella’s birth she caught a hospital bug that left her with pleurisy for a couple of years. Having just recovered, she was then in a car crash that trapped her in the back of an upturned car for about 30 minutes.

“I really thought I was going to croak. I said very efficient prayers — ‘Make Freddie meet someone nice, who’s really sweet to the girls, and make my parents live till they’re 309 so they can look after them.’ I remember sort of rising above myself and then being sucked back in and thinking, ‘Oh, maybe I’m going to be all right.’ ”

In hospital, she learnt she’d broken her foot and two bones in her back. For three days it seemed she’d never walk again. “I was on morphine so I was like, ‘Fine. I like reading anyway,’ but my mum went haywire at the news. Her thyroid and vision went wrong.”

For 18 months, Winkleman’s back was so painful she was unable to lift her tiny, confused children. Yet she refuses to do self-pity, saying her extensive charity work for, among many others, The Big Issue and Age UK, gives her “perspective. I visit parts of the country most of my friends don’t even know exist and see people living such bloody difficult lives. So I just think, ‘Shut up. You’re not allowed to complain about anything. You’re so lucky.’ ”

Wild Cherry begins on BBC1 on November 15

Hair: Lewis Pallett at Eighteen Management using Keune. Make-up: Julia Wren using Victoria Beckham Beauty