Making people laugh comes easily to Sheridan Smith, the actress best known for playing the love of Ralf Little's life in the sitcoms The Royle Family and Two Pints of Lager and a Packet of Crisps, and currently dishing up more mirth as a hypocritical nutritionist beset with life's difficulties in the new BBC3 TV comedy series Grownups.
Off-screen, she's infectiously bubbly, a lot of fun to be around and, it seems, seriously uninhibited. "I often flash my boobs," she admits. "My friends are used to seeing them and tell me to put them away."
It's hard to imagine Sheridan being glum. But a few years ago, shortly after moving to London from her native Lincolnshire, somthing happened that wiped the smile off her face.
"I was walking along when a girl dragged me into a doorway," she recalls. "She said she had a knife in her jacket and did I have any money. She said it a few times, as if she didn't believe my answer when I said I didn't. Lots of people were walking past but nobody took any notice. It was terrifying. I eventually jerked my arm from her grip and she ran off.
"Five minutes later I started shaking and crying, thinking 'What if...?' Coming from a village, I'd never known anything like that. I was only 17 and it made me think, 'Is this where I want to be?' But by evening my fear had turned to anger and I thought, 'How dare she? I'll have her!' Obviously, muggings happen everywhere and now I love London and stride confidently down the street. I know where I'm going."
Sheridan, 25 this week and back on TV later this year as matchmaker Cleo in comedy-drama Love Soup, is as brown as a berry when we meet at the Landmark London hotel, just across the road from the Open Air Theatre in Regent's Park where she has made her Shakespearean debut as Bianca in The Taming of the Shrew and Hermia in A Midsummer Night's Dream.
"I've just been to Cuba with my boyfriend. We went swimming with dolphins. It was amazing. Being in deep water was a triumph because when I was younger and learning to swim I strayed into the deep end and went under. I thought I'd had it, but my dad got me out. I had never been out of my depth since, so swimming with dophins was quite something."
Sheridan is one of Britain's most admired young comedy talents. Unmissable in 2003 as a pregnant Scouser in sitcom Eyes Down, and still closely identified as Janet in Two pints... and Emma in The Royle Family, she's now winning more fans as neurotic, fun-loving Michelle in Grownups.
"Michelle tries to tell everyone how to live their lives, but she's really a shambles in her own life, " she says. "She's 26, hurtling towards her thirties and wondering why she doesn't have a boyfriend and a mortgage. She thinks she's very grown-up but she still acts like a spoilt brat.
"I've been where Michelle is but I did it earlier. I wanted to buy my own place and still go partying and spend, spend, spend. I'm not like that now. I've got a boyfriend, a mortgage on a flat in north London and I'm happy being settled - but I'm definitely not grown up yet!"
She attributes her cheerful disposition to her upbringing. Her mum and dad, Marily and Colin, are Country and Western stars The Daltons; her brother Damian sings and plays guitar in the group Indie Manned, and boyfriend Jonathan Dixon is a bass player with different bands. "All I've ever known are people performing for a living." she says.
Sheridan herself started at a young age - she trained with the National Youth Music Theatre and appeared in the musicals Pendragon in New York and Bugsy Malone in the West End while still at school. "I used to sing with my parents, songs like Grandpa and They Don't Make Them Like My Daddy Any More. But Mum and Dad aren't showbizzy and if I started getting cocky, they'd soon bring me down to earth.
"They've been so inspirational. I've never known a time when I didn't want to perform and they put no barriers in my way. The best advice they gave me was to be nice to people and enjoy everything I do because it won't last forever. They've dragged me up well, as my mum's always saying!"
She laughs. "They're my greatest fans. They keep scrapbooks filled with press cuttings about me, and ring around the village when I'm on telly. When I was doing Bugsy Malone, they hire double-deckers to bring family and friends down to see me. Then for Sondheim's Into the Woods at the Donmar Warehouse, Mum brought a bus-load of people and they all went 'Hurraaaaay!' as I walked on stage. They organised coaches for my first Shakespeare too."
She's relishing her stint with the Open Air Theatre. "We did Dream at school and I loved Hermia - she's kind of feisty, like me - and staging it outdoors captures the magic of it."
But there'll be no post-show nights on the town for her. "People think I'm a real party animal, whereas I'm a homebody. There's nothing I love more than being with Jonathan and my dogs having quiet nights in."
The couple were brought together by a matchmaking friend. "I went to one of Jonathan's gigs and thought he was brilliant," she recalls, "When we met, it was his smile that did it. We hit it off imediately. We've been goether for over a year. I go to as many of his gigs as I can - I'm the screaming fan at the front! He's a real gentleman with a big heart. I'm a lucky girl."
She's also refreshingly aware of her own faults. "I can be annoyingly indecisive so Jonathan has to make the decisions for me," Sheridan admits. "I joined a gym in January but I've not been once. I keep saying, 'Do you think I should go?' And he says, 'Of course, it'll do you good.' I drive him crazy because I eat so much junk food - crisps, chocolate and takeaway pizza every night because I'm rubbish at cooking, unlike my mum."
Her parents have been married for 40 years and Sheridan says they're a tough act to follow. "I don't want to go through two or three marriages. I want to make sure the person I marry will be my partner for life. But I'm a bit of a rebel. I like being young, free and single. I'm 24 and I don't think I'll be able to commit to being a wife and mother until I've had some fun."
Fun pops up a lot in her conversation, not least when talking about her pal Ralf Little, who plays her husband in Two Pints.... "I was just 18 when I started playing Ralf's girlfriend in The Royle Family and we've grown up together. We've got a sort of brother/sister relationship."
Her career success has been impressive but it's certainly not something Sheridan takes for granted. "Every day, I think I'm so lucky to be doing something I really enjoy and that I have a loving family back home. Sometimes I can't believe it's really happening," she says.
"I look back on my days in Lincolnshire, when I was getting £20 for a 12-hour day working in a burger van saying, 'Do you want ketchup and onions on that, luv?' and I think, 'Wows! little old me has got these sitcoms and Shakespeare in the park.' I'm going to enjoy it while it lasts."
