Claire trained at the Oxford School of Drama after attending university in Liverpool where she focused on drama and screen studies.
'When I was a little girl, I trained as a ballet dancer,' she says. 'Then, when I was 13 I developed juvenile arthritis. That's when I began thinking about acting, although I never really thought I could do it.'
Here's Claire's description of the audition process for Little Dorrit:
'It's uncanny how this has turned out to be a story with a very modern connection, but I hadn't even read the book when I first auditioned because I was convinced I didn't stand a chance of getting the part', she says. 'All I knew was that it was a period drama.
'There were four auditions and for the first two with the casting director Rachel Freck I was struggling to get a grip on it all. I went in and read my lines and I got completely the wrong end of the stick. It was atrocious.'
Claire was lucky. Instead of being dismissed - as some tough casting directors might have done - Rachel Freck encouraged the young actress to try again.
'She said to me, "You can do it." So I spent a lot of time on it and finally read the book, which really helped because then I realised how Dickens had envisaged Amy Dorrit, and what the casting people wanted.
'Even when I found out we had gone down from 40 candidates to just three or four girls, I still thought I didn't stand a chance. Then I got the call saying they wanted me and I said: "Are you sure?" I thought right up until the last minute that they were going to turn round and say: "No, we've made a mistake!"'
But producer Lisa Osborne explains why they gave this plum role to an unknown with only three National Theatre plays and one TV drama, Being Human, to her credit. 'We were keen to find a girl who viewers wouldn't have seen before so she'd be fresh and believable as Amy Dorrit.
We'll also be seeing Claire next year in Season of the Witch, starring along side Nicholas Cage which is sure to raise her profile in the US.