It's a wrap

Success has come comparatively late for Camilla, 27. Four years older than Knightley, she is just appearing in her second film, A Bunch of Amateurs, co-written by Ian Hislop and produced by David Parfitt of Shakespeare in Love fame. In the film, she plays the daughter of a fading Hollywood great (Burt Reynolds) who thinks an offer to do King Lear in Stratford will resurrect his faltering career.

The rub is (and this is where the Richard Curtisstyle comedy comes in), it's not Stratford-upon-Avon, it's Stratford in Suffolk. 'Burt is such an old-school Hollywood star. He's a huge beast of a man, so gorgeous, and very charming. If he was 20 years younger...' she says in a deep flirtatious voice as she sips a glass of Malbec. 'He didn't like the cold, and struggled a bit with the Shakespeare. But the funniest thing was that there was Derek Jacobi, an RSC veteran, playing a poncey lawyer desperate to play King Lear.' In the style of Love Actually, the film features old British faithfuls including Jacobi, Imelda Staunton and Samantha Bond. Camilla plays the actor's spoilt princess of a daughter drafted in to play Cordelia. The film was chosen for the Queen and Prince Philip at the annual Royal Film Performance in November. 'They were laughing a lot so that was a good sign.'

Only Camilla's determination has seen her get this far: she was turned down by two drama schools and, after a Classics degree at Edinburgh, she spent a year as a barmaid, only acting in her spare time. 'Eddie Redmayne came into the pub one day. I was so depressed about my future, but he'd seen a play I'd done in Camden called Square One with my friend Theo Cross [directed by his father, actor Ben Cross, star of Chariots of Fire and The Far Pavilions], and he said, "Do not give up. Do not give up." After my next play [The Shape of Things by Neil LaBute at the Barons Court Theatre], this gorgeous silver-haired man comes over and asks to buy me a drink.' It was Dallas Smith, the agent of Sienna Miller, Rosamond Pike and Redmayne. He signed her a week later.

Camilla's versatility could be what sets her apart from the likes of Sienna Miller, who was a classmate at Francis Holland prep school in Sloane Square. In the past 18 months Camilla has played Keira Knightley's giggly confidante in The Duchess; a 'posh bitch' in Sex, the City and Me, a Channel 4 mockumentary about sexism in the workplace, with Sarah Parish; a meek scullery maid in a touring production of Festen; and a 'highly sexed art collector' in a remake of Minder, with Shane Richie. 'I really liked that one.'

Nothing about Camilla's background suggested that she would become an actress: her father Anthony Arfwedson is an HSBC banker, and his wife Kate is an interior designer. They arrived in London from Stockholm in the Seventies. Camilla and her older sister Christina, a journalist, grew up in a flat off the King's Road and their parents retired to Rye in East Sussex once the girls had left home. Camilla's boyfriend is a young actordirector, Alexander Gilmour, whose Look Back in Anger at the Jermyn Street Theatre earlier this year impressed the Evening Standard's theatre critic Nicholas de Jongh: 'Gilmour has given the play an exciting new dynamic and made a remarkable directorial debut.' The LAMDA and Oxfordtrained Gilmour is now 'smitten by the directing bug', she says.

Camilla, however, is happy to stick to acting. 'I was filming Miss Marple, with Jemma Redgrave playing my mum and Tim Brooke-Taylor playing my dad, and I thought to myself, "I want to act because I want to be the age of 60 and be naughty in between takes with a girl who's 40 years younger than me."'

A Bunch of Amateurs is out on 19 December.

Hair by Juan Carlos at One Make-up using Bumble and Bumble. Make-up by Denise Rabor at Caren. Fashion assistant: Hannah Bort