You're appearing in The Passion, the BBC One drama about the last week of the life of Jesus Christ. Are you a saint or sinner?

Sinner.

Care to expand?

Aren't we all sinners? That what's those sandwich-board guys with megaphones who stand on the street tell us.

Not religious, then?

Not at all.

What's your role in The Passion?

I play Abigail, the pregnant wife of Caiaphas, the High Priest who condemns Jesus to death.

Did the role involve giving birth, too?

Yes. The director wanted the birth scene to be over the top, so it's a screamy, shouty affair.

You had your first child, Lila, just over a year ago. Did you draw on experience?

Mostly I drew on the fear I felt before I gave birth. When I had Lila, I was screaming and shouting through panic and sheer terror rather than pain.

I wasn't sure what was going on and I was in labour for 36 hours, followed by an emergency C-section.

Enjoy the yummy-mummy lifestyle?

I claimed when I was pregnant that I might never act again. Then I decided I'd take a year off, but after I finished breast-feeding I was like: “I have got to get out of the house. I have got to do something.”

Ever feel guilty?

I think every mother feels that the best place for their child is with their mum, but you want things for yourself, too. So, you're either at work feeling guilty or you are at home feeling frustrated.

Did your mother work?

She was a nurse. When I was a child I really liked the smell of hospitals, because Mum smelt of them, so it meant she was home from work.

You play Florence Nightingale in a forthcoming BBC drama; did you dream of taking people's pulses as a young girl?

I wanted to be an air-hostess nurse, if such things ever existed. I liked the idea of flying all over the world and helping anyone who got sick on the plane. I used to feed my brother and sister little spoonfuls of water.

Your daughter has a stepbrother by your husband, Karl. Any sibling rivalry?

Billy is seven years older so there's no direct competition and he adores her.

So you're no evil stepmother?

It is harder to discipline and harder to love a child that is not your own, but we get on very well.

You used to be a party animal. Still joining in?

Oh, God. I wish I had never done that stuff. I used to take drugs and have a bit of a party lifestyle, but whenever I see anything about it in the press it is really embarrassing.

Nurse any regrets?

If you changed the course of events, everything would be different, so there's no point regretting it, but I do think taking drugs and partying like that was a big mistake.

Any vices left?

I'm addicted to nicotine tablets. It's definitely better than smoking, but I've just switched addictions.

Nicotine is an appetite suppressant; do you worry about paunches?

I think it's sad and really worrying that people are obsessed with their weight and looks. It cripples people.

So Lila won't be getting a subscription to Heat for her tenth birthday?

I hate to think that Lila will become obsessed by her body image, but it almost feels inevitable if the magazine culture we have now continues.

Are you a gym bunny?

I used to try to go to the gym but I've given up. I simply don't like it. Instead, I do Pilates once a week and make myself walk everywhere. I don't like driving as I had an accident not long ago.

What happened?

It was in January. A car hit us head-on. Nobody was killed, but I got severe whiplash and it aggravated a back injury I had while pregnant.

All fixed now?

No, it's a constant niggle. I tried acupuncture, which was good, but I needed something else. I found a good cranio- sacral therapist in Glasgow and that really worked.

Not London-bound like most actors?

No. I love Glasgow, it's where all my family and friends are. We can have a bigger house and you can walk to everything.

Quality of life before all else?

Definitely. I think that's more important than anything else, but so easy to lose sight of.

The final episode of The Passion is Sunday, BBC One, 7.30pm. The first three episodes are repeated from 2.15pm Sunday

Times recommends

• The pink mile: women on death row
• The top 10 richest streets in the world
• Japan's new professional seducers