Runaway bridesmaid

I'm ravenous!' purrs India Hicks' buttery voice above my head - like Daisy Buchanan's, it is full of money - and she unfurls in sections in front of me, beginning with a pair of erotic, spiky heels, followed in languorous succession by two shapely ankles, long, elegant legs, a natty black and white suit and a lean, aristocratic-face set with startlingly green eyes. 'Don't mind me!' she coos as she collects herself at the foot of the spiral staircase. 'I'm just coming to forage.'

It's 3pm on a photo shoot in Hoxton and the most celebrated bridesmaid at Charles and Diana's wedding is prowling toward the food in the kitchen. East London is a very long way from her day-to-day life: normally the 36-year-old lives on an idyllic Bahamian island measuring three miles by one.

India is Prince Charles's goddaughter, the granddaughter of the late Earl Mountbatten, and the one who got away - the society girl who ran off to a Caribbean island and got herself 'up the duff', as she once put it, by a man she had just met. It was a scenario that her mother, Lady Pamela Hicks, took amazingly well, as did Prince Charles ('Wonderful news,' he wrote gallantly. 'Amazing what the sun and the sand can do for you') - though her interior-decorator father, the late David Hicks, was not so amused. To be fair, David Flint Wood wasn't exactly unsuitable. He'd had a string of well-bred girlfriends, including Lady Helen Taylor and Susannah Constantine, and worked at Saatchi & Saatchi before moving to the Bahamas to manage a hotel.

Still, India's decision not to get married but instead to live in sin with Flint Wood on Harbour Island in the Bahamas raised eyebrows in the deeply grand circles in which she moved. Eight years on, the couple have three children, Felix, six, Amory, four, and Conrad, ten months - 'Three boys!' she shrieks. 'I must be being punished for something!' - and Hicks juggles interior design assignments with a modelling career and family commitments. She was recently in Miami doing a Bruce Weber shoot to launch Style, a new perfume by Ralph Lauren. Now she is on a brief visit to London to celebrate the 80th birthday of her aunt, Countess Mountbatten of Burma. She has Felix in tow, and says he has already zoomed round the Imperial War Museum and the zoo. India and David are living the paradise life most Londoners fantasise about. As if to underline this, they published a glossy interior design book last year called Island Life. This features pictures of their six-bedroom house - and if you weren't gnashing your teeth with envy before seeing it, you will be after. I tell her that, having read it, I'm convinced she lives in paradise. 'It is paradise,' she concedes, 'but it's a struggle as well. A lot of people wouldn't be suited to it. The best thing is not getting parking tickets. The worst thing is just the frustration of island living. If the boat doesn't come, there are certain groceries you won't get. And the power goes down an awful lot.' She grins. 'When I was breast-feeding last time round I was going away for a weekend, so I pumped a lot of milk and put it in the freezer. Then we had a power cut that went on for 12 hours and these precious bags of breast milk began to melt. I was running round the island with them, going, "Does anyone have a freezer?" '

She says what she misses most are lunches with girlfriends, photo-processing shops and the cinema. 'As soon as I get to Miami I rush to the movies. We have a phrase: "Time to get off the rock!" Sometimes I'll be walking down the beach with David and see someone and go, "He's good-looking." Then they'll pass and I'll go, "Oh my God, he's not good-looking at all!" David will laugh and say, "Time to get off the rock!"' One journalist, visiting India in Harbour Bay just after she moved there, saw a jagged hole in the floorboards that India had apparently made stamping her foot in a tantrum. She says with an easy laugh that David must have told that story. 'We do have rows, just like any relationship. And it is particularly weird because you can't even get in a car and drive somewhere, because there's nowhere to go. There's one road down and the same road back. But for seven years we seem to have managed - though God knows, I take things one day at a time.'

India Hicks was 13 and at Gordonstoun when she made headlines as the prettiest of Diana's five bridesmaids. She then did a photography degree in Boston where, at 22, she was spotted by Ralph Lauren and started modelling.

First in Paris, which she loathed - 'I came to modelling late, but it still makes you quite insecure, constantly being criticised. And Paris didn't suit me. I think I'm too relaxed for Paris.' So after three years she moved to New York, which she adored. 'It was buzzing at 3am - it never stops. I lived in the Village in a loft and Rollerbladed around and had a lot of gay friends.'

That lasted another three years. Then her nine-year relationship with Aris Comninos, a half-Greek businessman she'd met at Gordonstoun, came to an end.

'So I was in kind of a weird place. And with the modelling I thought, "I've done that now." And I met - re-met [she'd known him in childhood as one of her sister's best friends] - David at my parents' house, which is on another Bahamian island. And, as he always says, "One thing led to another and now he's six!"'

I ask why David left London in the first place, and India shakes her head in amazement. 'I don't know,' she says. 'I think he just thought, "A change!" He had a really good job at Saatchi & Saatchi and literally left with one suitcase. His mother was horrified. Horrified! And then I got pregnant --far too quickly. After four months! But that suited me, because I would never have made the decision otherwise - I'd have kept running round the world living a nomadic life thinking I was happy, when nothing has made me happier than having children.'

Not long after they got together, David gave up managing the hotel, and he now doesn't have a job, but paints, does some creative writing and works with India on her decorating projects. He has no money of his own, which may be why they agreed to write Island Life; the couple also let out their guesthouse, which they have built on to the house. The family's money comes largely from India's modelling and decorating work. She got defensive years ago when she was asked if she was the breadwinner. 'Part of the reason that David fell in love with Harbour Island is that deep down he wanted to write,' was her take on it then. 'David will never have a penny in his life, and absolutely doesn't care.'

He is, she says, totally different to her. 'I'm full on, full of energy, very athletic - I lead a pretty healthy life. He complements that by smoking and drinking a great deal! He's never done a day's exercise in his life, he's very oldfashioned, extremely intelligent and very well-read.'

It was David who wanted them to marry and India who said no. She seems to find the idea incredibly claustrophobic, probably because she had an unhappy childhood and possibly because she was not very inspired by her parents' marriage - she was brought up by nannies in attics, taken to school in a Rolls-Royce and says she barely saw her parents. She has described her father as a very difficult man. 'But it's such a personal thing,' she says diplomatically. 'At the moment marriage is not something I need particularly, and I do see many crumbling all around, often after a very few years.'

One of those she may have in mind is Charles and Diana's. 'I have many memories of the wedding, particularly her scent - Diana wore tea rose, which influenced me a lot as a teenager,' she says of that extraordinary day in 1981. 'We helped her get dressed. She was in jeans and tiara, the TV next to her, and she kept shooing everyone away so she could watch it. Now, as an adult, looking back, I think she was so young. So young! I remember she got to the bottom of the staircase at Clarence House in her wedding dress, and everything was on such a tight schedule, and said, "I need a glass of water." Twenty-three footmen ran to get her a glass of water. Then she stepped outside and the world changed.' I ask India if living in the Bahamas means she has left that aristocratic existence behind. 'I have. On Harbour Island I have friends that perhaps I never would have had otherwise, and there aren't many pretences: it's very much about whether the boat's coming and what the day brings.' It seems to agree with her. In her early days there she said once that it was 'paradise in its way, but it is very isolated. There is really no one I can turn to,' and came across as a bit troubled, insisting that she wasn't the 'nice' person she seemed and that she was difficult to live with. Now, she seems happy in her own skin. She swims before breakfast, ferries the children to school in pyjamas and spends her mornings at her boutique (it stocks fashion by her sister-in-law Allegra Hicks, Diane von Furstenberg and Elle Macpherson). In the evening, if they have guests, she will get in a cook. This is increasingly necessary as her island has become the most fashionable destination in the world - particularly at Easter. The only cloud on the horizon is the children's education. At the moment Felix goes to a tiny private school on the island, but eventually India thinks he will have to be educated in England. She seems laid-back about it. 'I'm pretty religious about running,' she says. 'I have a dog, and he and I run most days on the beach. It's at that moment I feel: "This is why I'm here." People always say, "Why do you live there?" I tell them: "Because I have a three-mile pink-sand beach at the bottom of my garden!"'