I had a wonderful childhood and wonderful parents,’ says Sarah Brightman. ‘We lived in a four-bedroom house in Berkhampstead that my father built. I went to a stage boarding school when I was 11 and I was unhappy there. I remember my father saying to me, ‘Make up your own mind. You can either come home and do something else, or if you’re ambitious, you’ll have to stay on at the school’.

‘In the end, I stayed on because there wasn’t a stage school in our area. But to be honest, I would have preferred to have remained at home. I loved my family so much that I didn’t want to be away.’

So Sarah, the eldest of six children, went to private school though, in the early days, her sisters were sent to grammar schools. ‘They went private as my father’s business got better. He started from simple beginnings and did very well for himself and his company. We had a good lifestyle.’ She also says she inherited a disposition to insomnia from her father. ‘I don’t sleep well because I’m always worrying about the next thing.’ (She looks radiantly healthy, bright-eyed and rested.) ‘I think I’m one of those people who can survive on four hours’ sleep a night. My father is like that.’

Only days after Sarah spoke to me, her property developer father, 57 year-old Grenville, was found dead in his fume-filled Golf GTi. His marriage to her mother, Paula, ended five years ago and he is thought to have been having a complicated romance and business losses. It is significant that it is to her mother that she goes to stay in her spare time, on the south coast. It is also significant that she told me how important her ‘wonderful’ family had been to her in the 18 months since she was divorced from her second husband, composer Andrew Lloyd Webber.

Despite her father’s tragic death, she showed up this week to play her part of Rose (a woman who has lost in love) in her ex-husband’s Aspects of Love. Work provides a safe haven for her. ‘I can lose myself completely in my characters,’ she said last week, kicking her leg at an imaginary football, as she did through much of our time together. ‘I love escaping. I’m not saying that one wants to escape from the day, but it’s lovely to be someone else.’

In similar fashion, playing Rose helped her to overcome the break-up of her marriage. ‘It was quite therapeutic. If you work and have something that you can cling onto, that is the best thing you can do. Work is the one thing I know I do excellently. It gives me stability.’ She talks in a guileless fashion and presents herself like a little girl.

She says that since becoming single, she has become stronger. ‘I am opening up and becoming stronger as a person and a performer. I’m becoming stronger because I’ve had a lot of personal things to deal with. I’m not going to go into them, because they’re obvious. But I’ve also had to go through a lot of barriers career-wise.’

Married since the age of 18 (first time to a band manager called Andrew Graham-Stewart), she has coped well. ‘I’ve always been very reliant on a man. But I’ve handled it really well. I’ve not stopped working since I got divorced, I’ve lived in another country (America) and I’ve dealt with things for the first time by myself. I haven’t had anyone to go to and say, ‘I’m scared about making this decision, what do you think?’ ‘

Does she still feel hurt about Lloyd Webber? ‘I never felt hurt.’ Seriously? ‘No, I never felt hurt.’

‘He went off with another woman and you didn’t feel hurt,’ I say. ‘I have never felt hurt and I’m being truthful.’

She says they work together happily today. ‘There aren’t really any negative things to say.’ So why did he leave her? ‘You’ll have to ask him.’ She laughs. ‘He obviously had his reasons and did it.’ She appears incredibly accepting. ‘I don’t think one has any choice in life.’ He settled on her a sum that she won’t disclose, but estimates have been in the region of £6 million. ‘I live off my earnings and I wake up like everybody else, panicking in the night because I have bills to pay.’ Curiouser and curiouser. Why does she feel the need to panic in the night when she has some tidy sum stashed away? ‘Because I like to live in a real situation. I can’t do my job unless I’m in it with everybody else and I know what they’re thinking. How can you go into a meeting and negotiate when your head is in Timbuktu?’

She has left behind a lavish lifestyle. She will tell you how it didn’t change her. (‘I wasn’t any different.) And how she would do things like go to the White House or meet the Prime Minister. But nowadays she lives a quieter life.

One of the things that helped her make this change was her faith. ‘How am I going to say this without sounding cranky?’ She sometimes chooses her words carefully and talks in a circumspect fashion, as if she fears being stitched up. ‘My mother and two sisters are Catholic. Religiously, I haven’t anything very strong in my background. But I feel a very strong force within myself, almost like an instinct which I follow.’ She places her hand on her stomach. ‘It is warm and it is bright. I suppose you could call that God. I know that what keeps me going is this strong, warm force inside me. ‘I think you have to be very humble about what you want to achieve in life, because it’s not our decision,’ she says. ‘I don’t say I’ll leave everything to fate, because I certainly wouldn’t. But there is a fair amount of that. You can plan your life for the next 20 years, but there is no way it is going to go that way.’

When she talks about her split from Lloyd Webber, she talks about such cosmic forces again. ‘There are forces and things that happen that are completely beyond our control. Relationships aren’t like business and you can’t treat them as such. If someone really truly loves you and you’re just yourself with them and not forcing anything and it is right, it will be there forever. But if it’s not right, it’s naturally not going to work.’ She now lives in a two-bedroom rented flat in central London. She has simple tastes. ‘I’ve got the basics. I don’t need anything else. I don’t own a property anywhere in the world.’

She is 31 years old. ‘I don’t mind if I never get married again,’ she says. ‘And that’s not to do with being cross or anything. I don’t have a particular boyfriend. I’m dating lots of men. At first, I was a bit nervous because I didn’t know what to do. But you don’t have to do anything. You just have to be yourself.

‘I badly need people. We all do. I mean ‘no man is an island unto himself’.’ She leans back on the fleur-de-lis cushion in a hospitality room in the bowels of the Prince of Wales Theatre. ‘We all need help and advice. But inside, I am very, very strong and quite tough and I know what I want. I can be very independent, as long as I have my friends and family.’ Ask her about having children and she shrieks with laughter and starts to kick her leg in a very agitated way. ‘I come from a family of six, the youngest of whom is only 13. So I don’t particularly have any great maternal instincts. I’ve seen it’s jolly hard. I’ve seen my mother bring up all those children without any help. It’s tough.

‘In a way, they do drain your emotions and I feel that I wouldn’t be able to do my work as well if I had babies. If I had children, I’d probably give up all my time and stop work.’

It is unlikely she will stop work soon. She is driven. If she has two hours when the phone isn’t ringing, she starts to pace the flat. ‘Even if I switch on the television and watch a film, my mind’s grinding about why something is such and such a way at work and which camera shot would be good.’

She says she feels like the lion in The Wizard of Oz. ‘The one who has no courage. I’ve always felt like that since I was small. I’ve always felt like I’ve got a hurdle to overcome and often I don’t know whether I’m going to make it. There are all sorts of little things in life that I am scared of. And I am fearful of people.

‘But I’m also very happy within myself and feel quite strongly within myself at the moment.’ She does a double take on the last few words. ‘I’m healthy. I have a lovely family. And I have been given a talent that I feel grateful for.’

So why did she flinch on the last few words? Is it because she always thinks there’s something nasty around the corner? ‘I don’t know.’ She shrugs her shoulders, little girl like. ‘Maybe.’