Life is beautiful for Natalia Vodianova

I am not sure why it feels more surreal to meet the supermodel Natalia Vodianova than any other celebrity. Maybe because I've seen her so often in glossy magazines looking impossibly beautiful and poised in a tiny designer confection, always with her husband Justin Portman, the father of her three children. Maybe it's because they are clearly so happily married. But it's mostly because of the fairy tale – the 27-year-old who grew up starving in Russia and went on to win the biggest modelling contract in the world as the face of Calvin Klein, the same contract that turned Kate Moss into Kate Moss in the Nineties.

In 2002, Natalia married her husband in a sumptuous St Petersburg wedding ceremony that lasted three days. Tom Ford made her dress, in pale grey satin with silver thread. The guests, from Paris, London, and New York, were dazzled by the revelries, the highlight of which was a private performance by the stars of the Kirov Ballet in Peter the Great's throne room in Peterhof Palace. Now Natalia earns some £3 million a year, and when she and her husband are not hanging out with the fashion world's power players (Mario Testino, Valentino, Dasha Zhukova), they live in an old West Sussex mill house, a few counties away from the Portman family 3,000-acre Herefordshire estate. Justin's half-brother Christopher, the 10th Viscount Portman, also owns 100 acres around Portman
Square and Oxford Street.

I am expecting a castle-like pile, but the entrance has small sun-bleached wooden gates that swing inward to reveal a long, low mill house. At a long kitchen table Natalia and Justin turn towards me. They have their heads together and exude happiness.

She is in pale pink shorts and blue stripy boat-necked T-shirt; he is also in shorts, smoking, his head in an origami book, as he makes a minute green paper chair. He's a total addict.' Natalia observes, looking at him fondly. He's addicted to
origami, and to moths.' A cardboard box of moth preservative, in fact, sits next to him.

You'll make me sound like a mad eccentric,'
he protests.

Natalia leads me next door, where she pulls her long legs up on to the deep red sofa. Now it seems slightly absurd that I worried about drying my hair; hers looks as if it might have got caught in a hedge. She is wearing no make-up and her eyes, a pale, metallic blue under faint eyelashes, are wide set. Just as their house is far more down-to-earth than I had expected, she is
startlingly different from her pictures. Utterly unlike her chic, varnished alter ego, she is open and trusting. But when her face catches the sunlight, I see why the camera loves her.

I ask how this girl from Nizhni Novgorod likes the English countryside. Oh my goodness, I absolutely love it,' she cries in her slow, Russian-accented English, her face lighting up. I have a horse I can ride, I have a bicycle I cycle everywhere, one of Justin's brothers and his family live 15 minutes from here, we do play dates, it's all about children.

And we walk on the South Downs, looking at butterflies and wildlife. Justin's very into nature; we do a lot of very fun things like moth-hunting nights!' She grins.

Most people look at me, like, "What?" And Justin cooks; we are very social, we always have people to stay. It's so much more peaceful and less dangerous and slower-paced and I can be like this,' she gestures at her clothes. When I used to live in New York and then London it wasn't the same, I wasn't a happy person as much as I am now.'

The couple spend almost all their time here, though they have a Manhattan apartment and are building a holiday home in Uruguay. Having finished her contract for Calvin Klein, Natalia is concentrating on her charity, the Naked Heart Foundation, and her children. Lucas is seven, her daughter Neva is three and her youngest, Viktor,
was two on 12 September. I could have ten more!' she admits a little wryly. My friend, I have a very good friend, we had our children one after the other, always being pregnant together, and we just found out that she's pregnant again. But I'm like, "Oh, I'm not catching up with you any more!"
I have an incredible nanny, Angie, she's like a sister to me, she's English, from Newcastle, she's been with us four years now. Before I was really struggling and it was very hard because I think I went through about 30 nannies. No one would put their soul into it.' Natalia got pregnant at 19, two months into her relationship
with Justin, and after she had Lucas, her career went nuclear. Nearly ten years on, the relationship is clearly flourishing, though the couple could not be more different.

I think it was the right timing for me,' she says. I was completely ready. I always wanted children.' The pair met nine months after she left Russia for Paris to model, at a dinner at the Pompidou Centre. She liked Justin immediately. But he seemed besotted by her friend, another model from Russia, until he came round the table halfway through and sat on the
arm of her chair. I'd had two vodkas by then and I looked at him and had this "What are you doing here?" reaction. I was quite straightforward at the time, quite Russian about things! I said, "You just left my girlfriend and sat on my chair. Do you think you can sit with my girlfriend for a little bit and sit with me for a little bit? It's not going to work like this!" And we started to fight and he was like, "Don't be such a bitch!" And my grandfather speaks to my grandmother like she's just an angel, so I was in complete shock and apparently I put a cigarette out on him!' She bursts out in a musical laugh. I don't remember that. I really liked him: that was the problem. And I am very proud, he was wealthy and I felt I would be devastated if I was with someone unequal to me.'