I don’t generally believe actors who claim to be shy. Who insist that crippling introversion is what drew them to the West End, to the BBC, to Broadway or Hollywood. Claudia Jessie, however, might just convince me. “Adjoa [Andoh], who plays Bridgerton’s Lady Danbury, said to me, ‘Are you a shouty shy person, Claudia?’” She grins and shrugs. “And I was like, ‘Oh my God, that’s what I am, aren’t I? I’m a shouty shy person.’”

Today, sitting cross-legged on a sofa, in the corner of a south London studio, Jessie has not yet done any shouting. She has, however, revealed herself to be a bag of contradictions. The breakout star of Bridgerton, in which she plays the privileged, ambitious, bookish and bonneted 17-year-old Eloise, Jessie is, in real life, a 31-year-old self-confessed “scruffbag”, a vegan Buddhist who left school at 14, and who now lives on a canal boat with her boyfriend. In Birmingham. Who appears cheerful, chatty and breezily confident, but talks openly about her panic attacks and depression. Who hasn’t bought new clothes in six years, and firmly refuses to engage with social media.

In fact, if it weren’t for her co-star Nicola Coughlan, who regularly sends her “cute screengrabs”, she might never have known that the Netflix drama in which they star is the streaming service’s most successful ever, with 82 million households viewing it in its first month.

Jessie fully understands its frothy appeal. “It’s nice to see things that are beautiful. We’ve all had such a rough time. People have lost jobs, lost lives. It’s OK to enjoy seeing people waltz at balls and shag in libraries.”

Not that Eloise, the spirited second eldest daughter of the eight Bridgerton siblings, and best friend to Penelope Featherington, aka Coughlan, aka the show’s mysterious gossip fount Lady Whistledown, is remotely into waltzing or shagging. Yet. Part of the rompy, Regency-set drama’s premise is the blithe, slightly disturbing ignorance of the Bridgerton girls about reproduction, which caused issues for eldest sister Daphne (Phoebe Dynevor) after her wedding to the dashing Duke of Hastings (Regé-Jean Page) in series one.

This afternoon, Jessie could not be less in character, in white vegan trainers, rolled-up Levi’s and a black jumper, all of which, along with her houndstooth tweed coat, are secondhand – the only way she shops, including for red carpet outfits.

Jessie is, in real life, a 31-year-old self-confessed “scruffbag”, a vegan Buddhist who left school at 14.

So, when she was approached by Barnardo’s to front its campaign, appealing to shoppers to buy preloved instead of new, it felt like the right fit. “I don’t do a lot of photo shoots – I get nervous about things like that,” admits Jessie. “But if something comes up that I care about, I’m keen.” (She recently gave an interview to Waterways World magazine.)

Barnardo’s lost an estimated $1.8 million each week that its 700 UK stores were closed during the pandemic, leaving it less able to protect those it is set up to help. “And it supports vulnerable young adults, carers, foster parents, people living with mental health issues – it’s such a wide spectrum.”

Jessie learnt to rummage her way around charity shops from her mom, Dawn, a single parent for most of her childhood. “We’d find Calvin Klein suits and Laura Ashley dresses that my mum and I would alter. But there was always bit of a stigma around it. I couldn’t be happier that that’s no longer the case.”

Born in Birmingham, Jessie and her brother, David, five years her senior, spent much of their upbringing in north London (her accent barely contains a trace of Brum), “but then moved here and there a bit”, she says, vaguely, including a few years living on a barge. You get the sense that things were a bit chaotic. Theirs was, she says, “a classic council-estate, single-mum household. Mum worked her arse off, cleaned houses, took me with her.” And, after Jessie left school at 14, homeschooled her too.

“I was a big reader, and always had my head in a book, but I was quite introverted,” she says. “I did well at school, but I just found the environment quite difficult.” She doesn’t have a single GCSE to her name, let alone A-levels or a degree. Her lack of formal qualifications and training has worried her “immensely, absolutely”, over the years, she admits.

The Netflix drama in which she stars is the streaming service’s most successful ever, with 82 million households viewing it in its first month.

Although she’s not sure drama school would have been the right fit. “I don’t know how much I’d have thrived in that environment. I think I’ve got more of a back-up-against-the-wall sort of mentality, Artful Dodger-ing my way about, elbowing my way into places.”

While money was tight, Dawn “would get me a ballet lesson or a viola lesson in exchange for cleaning a house. And she’d do the same with my brother with football. She’s incredibly resourceful,” says Jessie. “And things were rough – there were bailiffs at the door. My dad left us in a lot of shit.” She last saw her father when she was ten years old. Jessie is her middle name, but “I have no connection with my surname [Peyton],” so she dropped it for work.

Jessie began working in bars at 17, collecting glasses until she was old enough to serve, and as a dog walker, and as a promo girl for radio stations. “Which sounds sexier than it was. I just wore a tracksuit and jumped out at people being like, ‘Do you want to see JLS?’”

But, she says, “There was a point where I thought: I don’t want to hate my life.” She toyed with stand-up, and started to compere comedy nights around Birmingham. There she was spotted by Hannah Phillips, a local playwright and director, who recruited her for her theater company. “We did this play called The Fear of Queer, for one night, on my 21st birthday, and I remember thinking, ‘Oh. Maybe it’s acting, then.’”

She moved to London, slept on sofas for months, then became a guardian of vacant properties – “old halfway houses, doctors’ surgeries, places like that” – while emailing “every agent in the UK, and hand-delivering letters to the ones in London too”. Her mom put together a showreel, which, she says, was “shocking”. After months of rejections, the agent Michael Ford called her; next year, he will have represented Jessie for a decade. “He took a chance, because I had no experience.”

She still thought she’d veer toward comedy. “And then I started getting parts for fancy period dramas [such as ITV’s Vanity Fair, in which she played Amelia Sedley] and Line of Duty [in which she played Jodie Taylor, Thandiwe Newton’s sidekick], the least funny show in the world. Brilliant, but deeply unfunny.”

Then came the barnstorming Bridgerton, in which she does, at least, get to flex her comedy chops a little. For many fans of the show, however, a shadow has been cast with the unexpected exit of Page. The hitherto unknown British-Zimbabwean actor, who was catapulted to heartthrob status, announced in April that he would not be returning for series two.

Jessie had no idea he wasn’t coming back either, but says, with deft diplomacy, that she “couldn’t feel more blessed that Jonny Bailey [who plays the eldest Bridgerton brother, Anthony] is steering the ship”, as the new male lead. “He’s so spectacular at his job, it makes me a bit sick. It’s almost unnecessary, how good he is at acting.”

Although Jessie’s lips are contractually sealed as to what’s coming next season, currently filming on locations around London, “We’re going to see all of the things we love about Eloise – her desire to explore, that inquisitive mind – expand,” she says. And, since the truculent, sassy Eloise will be forced to make her own “debut” in polite society, it’s safe to say this will be Jessie’s season.

In an era in which marriage and children were a well-born woman’s only obvious destiny, Eloise’s bid for autonomy, adventure and intellectual stimulation evokes a certain Bloomsbury spirit, and has garnered the character a solid queer fan base.

That wasn’t, says Jessie, a conscious choice. “I think it’s interesting that we see this young woman who’s not walking or dancing in the same way as the other girls, not having the same desires women are taught to have, that it evokes a queer spirit,” says Jessie.

And then, of course, there are the frocks – acres of lace, empire lines and corseted, winched-up bosoms. A staggering 7,500 costumes were designed and made, by hand, for series one. “The costumes are even more beautiful [this series],” says Jessie. “I’ve cried three times at work already, because I can’t believe what I’m wearing.” She’s blown away by the speed at which the army of embellishers and embroiderers work. “A costume goes from a pattern to a full outfit overnight.”

She still finds many social environments challenging. “I’m the recluse on Bridgerton. I don’t really do big parties. I’m more into nursing a Sessions IPA for a couple of hours with a pal, and smoking a couple of rollies.” She’s suffered “hundreds” of panic attacks. “And I get aftershocks too.” She’s also suffered serious bouts of depression, to the point of feeling suicidal at 17, with “dodgy moments in my early twenties too. None of us is immune, of course, but I think I have a propensity,” she says. “A lot of us have overactive fire detectors. Mine’s going off when the toaster’s on, rather than when there’s a fire.”

While filming Vanity Fair she also suffered a severe, six-month-long bout of depersonalization disorder, which sounds, frankly, terrifying. “It’s an incredibly intelligent thing your body does where you’ve reached peak anxiety, and you blow the cap off, and your body goes, ‘I can’t be here if you’re going to continue to feel like this, so we’re just going to separate you from it for a little while.’ It makes you feel like you don’t exist and you’re living in a separate reality,” she says.

Buddhism has helped. She is a “noisy Buddhist – same sort as Tina Turner”, which involves a lot of chanting, often from 4.30am, along with “breathing, walking and talking”. “I find it very difficult to talk about stuff. I come from that culture of [she motions rolling her sleeves up], ‘Come on, we haven’t got time. Let’s just crack on.’ But depersonalization taught me I had to speak to people about things.”

She’s also suffered serious bouts of depression, to the point of feeling suicidal at 17.

Her refusal to participate in social media also undoubtedly helps. “I don’t want to get towards the end of my life and realize I spent it looking at my phone,” she says. “And not all of us are built to be able to use it healthily. I think I’d probably use it as a bit of a tool to hate myself with.” Anyway, she says, “I don’t want to hear good things people are saying about me, I don’t want to hear bad things, because either way it’s not real.”

What is very real, however, is the 57ft houseboat she bought three years ago. “It’s been a dream of mine forever.” Her boyfriend – whom she doesn’t want to name – “had never stepped on a boat before in his life, and he’s better than me at steering it, and I’m furious about it”. She’s living in London temporarily, while filming Bridgerton, but plans to get back to Birmingham, and the boat, and the boyfriend, as soon as possible. “I can’t see a reason to leave,” she says of her unstarry hometown.

Surely, though, she must have been getting offers from further afield – America, even – given what a global hit Bridgerton has been? “No.” Really? “No. I don’t think so. If I have, I don’t know about them.”

I’m not sure I can quite see the wry, witty, self-deprecating Jessie in Los Angeles anyway, with its selfie culture and rampant conspicuous consumption. “We live at such a speed, and everything has become so obnoxiously easy for us,” she says. “I could choose my life partner with my thumb. I could have dinner delivered in 30 minutes or an outfit from across the world in 24 hours.” With Birmingham, however, “it’s just a step away from London but it’s a slower pace,” she says. “And I love rooting for the underdog. People think Birmingham is so shit. And I’m happy with them thinking it’s shit,” she laughs. “Our house prices will stay low.”

Jane Mulkerrins is a London-based journalist