Emily Mortimer's recent roles as Ewan McGregor's abused girlfriend in Young Adam and flapper Nina Blount in Stephen Fry's Bright Young Things have been eclipsed somewhat by her latest life-changing role as a mum.

She is herself the daughter of a famous father, author John Mortimer, but has quickly made a name for herself in films such as Scream 3, Love's Labour's Lost, Lovely & Amazing, and The 51st State.

You've worked a lot in Hollywood in recent years, but here you are starring in two British films. Where do you and partner Alessandro Nirola consider home?

We're hesitantly based in LA. I came back to have the baby [in the UK]. I'm based in both places, I think. I live somewhere between the two, in a Virgin Premium Economy seat.

Despite the very specific period setting, Bright Young Things seems quite a modern film, in terms of pace if nothing else. What was your impression of it when you saw it?

I think it looks so confident, that's what really struck me. I was very aware on set that Stephen was so deft and knew when he'd got what he wanted, which is very rare for any director. I think it was Feydeau who said that comedy is tragedy at a million revolutions a second. That's sort of what this film is - tragedy speeded up.

Of course it's pure chance that the dark and gritty Young Adam was released just a week before the very different Bright Young Things. But being able to demonstrate that contrast is no bad thing for an actress, is it?

We're hired hands really, it's very hard to pretend that you really have any control at all over the choices you make. Actually in the last couple of years I have been able to slightly pick and choose in a way that I hadn't before but not in any grand way. It's become more possible to turn things, down basically. What I don't want is to just be known for one thing - that's what I'm scared of.

You keep great company in the film, with a raft of star cameos. Was anyone a particular hero of yours?

Stockard Channing. I saw Grease five times as a kid, but unfortunately didn't get to spend much time with her on set. But it was pretty thrilling to meet all those people. John Mills was amazing. To sit at lunch at Pinewood, and hear him talk about the old days, I felt like we had suddenly gone back 50 years. It felt very old school.

And there's also the sense that Stephen Fry has discovered a new generation of fine young actors too?

That was really thrilling, seeing all these undiscovered young actors who were so good, feeling like they were bringing such a breath of fresh air to the film. That was the most thrilling bit as far as the cast was concerned - meeting these real young bright young things.