Amber Valletta

When Amber Valletta turned up for her first photo-shoot for American Vogue, aged 17, the legendary stylist Brana Wolf took one look at her and shook her head. "I'll never forget it," says Valletta today. "She said, 'You're cute, sweetie, but we're going to shoot most of the fashion on Shalom [Harlow, the Canadian model] because she looks better in the clothes.'"

"I was totally gutted," Valletta says with a laugh. "Arthur Elgort [the photographer] was smoking his pipe and said, 'Don't worry, darling. I'll shoot some beauty on you.' And he did. I ended up getting a Vogue cover on my first sitting. From that moment on I never stopped working."

Valletta, now 40, is still shooting covers. So far she has had 16 American Vogue covers - more than Shalom Harlow and Kate Moss combined - and has appeared on the cover of dozens of other magazines, as well as being the face of Louis Vuitton, Calvin Klein and Versace. She has also forged a successful career as an actress, with more than 20 credits, including the film Hitch (2005) and the television drama Revenge (2011-2014). Recently, alongside Sean Bean, she started shooting the new series Legends, a thriller developed by one of the producers behind Homeland and 24.

And as if being a supermodel and actress were not enough, she also launched an online store, Master & Muse, in September last year. It features designers who focus on "ethical consumerism": "As a woman who loves fashion but wanted to buy things that were responsibly made, I know that there was nowhere to do it... Eventually I'd like to start my own label, but I wanted to understand the business first." It is, she says, her most fulfilling role to date. "In acting and modelling I am always part of someone else's vision. I love having a little bit more control over my destiny."

She arrives at the West Hollywood hotel where our shoot is taking place wearing a vintage white billowy shirt, vintage jeans and brown suede ankle boots from Yves Saint Laurent. She says that she doesn't spend much on clothing. "I'm not really an excessive person. I'd rather spend more on other things, like my garden."

Her face bears no trace of make-up (at least, before the make-up artist gets to her) but her distinctive pale-green eyes and angular bone structure make her instantly striking. At first she is a little clipped and aloof, but she mellows as the day goes on. She is very much in control of what is happening around her, suggesting outfits and changes to her make-up, but she is polite and friendly, calling everyone "honey" or "girlfriend", and making a point of thanking each person individually, from the photographer's assistant to the hair stylist. Throughout the day she fuels herself on miniature bottles of ferocioussounding juice combinations such as "ginger, lemon, cayenne and echinacea".

Born in Arizona, Valletta grew up in Tulsa, Oklahoma, and endured a rough childhood. Her parents separated when Amber was two and her mother battled to keep the family afloat. "My mom never gave up. She was broke enough to be taking food stamps but she worked her a— off to keep us in school and to put food on the table. She waitressed, then started delivering mail for the post office and worked her way up into the corporate part of the post office."

Valletta says that she draws much of her strength from her mother, who was a forceful activist, landing herself in jail on one occasion for protesting against a nuclear plant. "It was pretty scary hearing that your mom got put in jail - but I saw what it meant to fight for something you believe in. My family is matriarchal. The women are definitely the rock of the family. We call my grandmother Queen Mary. I think it was just engrained in me to be a strong woman."

She spent weekends and holidays on her grandparents' farm. "They bred horses, but nothing fancy. We had goats and peacocks and a creek that ran through their farm so we had snakes and fish and frogs. It was really, really fun. I feel blessed that I had such a great childhood with a really strong family."

Yet a few minutes later she is talking about "letting go" of trauma in her childhood. "I've forgiven both of my parents. They're human beings and they tried the best that they could." She doesn't specify where her mother went wrong, except to say: "She made mistakes, she was young and had two kids and no education and was trying to make ends meet."

When Amber was 15, her mother enrolled her in modelling classes and, at 17, she was offered a summer job modelling in Italy. "Looking back now there's a part of me that wishes I had taken one more year to be a kid at home." As she rocketed on to the international modelling scene, she says she often felt overwhelmed: "So much was happening and, although I was street smart, I wasn't worldly smart, I didn't know anything about anything. I was terribly insecure. I hadn't caught up to being a big supermodel."

The first model who made a real impact on her was Carla Bruni. "She was a very gracious woman. The first time she saw me in a fashion show, she came up and introduced herself. I remember a season or two later, after I'd hit my stride and was probably feeling a little bit big for my breeches, I walked into a room and didn't say hello to her. She came over and said, 'Don't be impolite' - and I really heard it."

She remembers meeting Kate Moss for the first time when Harlow, who was living with Valletta, brought Moss around: "She was just this tiny little thing and nobody knew her. The three of us started running round together and then she hooked up with Christy and Naomi. There were pods of us - we were like sorority sisters. We had a lot of fun. I can't give you any details because we're all sworn to secrecy. But what we did was ridiculous, the stuff you would do if you were in college - like dressing up in the middle of the night and knocking on people's doors. Can you imagine opening your door and Kate and Naomi and I are standing there in wigs and sweatshirts?"

She says that she became friends with all the supermodels of her day. "Christy, Naomi, Linda, Shalom and Kate were my crew. And Kirsty Hume and Stella Tennant too - Stella was hilarious. I remember she couldn't walk in the Versace shoes... When I see Stella now it's like seeing a sister, and the same with the other girls."

But it wasn't all fun. Valletta says she was susceptible to the many temptations of her newfound world, particularly alcohol. But she doesn't blame the industry per se. "Let me put it this way: I would have found it if I'd been in college, wherever I was, because that is part of who I am. I've been clean and sober 15 years now. I was an all-ornothing kind of girl and it was not working for me. I really believe I'm an addict through and through. It runs in my family."

She thinks the negative connotations around addiction are unfair: "It is a real disease, like being allergic to sugar or to bee stings. And it's still treated as something shameful: if you were strong enough you would fix it. If you were strong enough, could you fix breast cancer? No: you have a f— disease - it's a biochemical, physiological disease."

Occasionally she is still tempted but never succumbs. "Every once in a while, I'll miss a glass of wine. And there are drinks that I've never tried and I think, 'S—, I should have tried that.' But I'm so much better without it - the risk I take if I have something is too big. I don't know where it will lead me."

A few years ago she went into rehab but for different reasons: "It was an internal house-cleaning - I needed to learn how to let go of the wreckage and live freely today."

Valletta's first marriage, at 20, was to the French male model Hervé le Bihan - but the couple divorced two years later and she is now married to the Olympic volleyball player Chip McCaw. She had bumped into him when she was home in Oklahoma visiting her mother. "We met in a store with our parents and they set us up on a date." Was she resistant? "No, I thought he was cute." They have a 13-year-old son called Auden who "towers over me at 5ft 11in".

Turning 40 was not a big milestone for her. "It meant a lot more to everybody else around me. I didn't want a big party, I just wanted to do 40 great things this year. So far, I've learnt to surf properly. I rode a mechanical bull. I went to Austin with my son. I went to see Justin Timberlake..."

And a couple of days before we meet, she pierced the top of her left ear.

"I was scared s—less, but I wanted to do something fun and slightly rebellious - I've always had a rebellious part of me." She confesses to having had second thoughts. "I asked my son, 'Do you think this is embarrassing?' and he said, 'No, it's cool.' If he didn't like it I would take it out."

Valletta made the switch from modelling to acting because, she says, "I needed the stimulation of something more and felt I had to do something else to be taken seriously. Had I known back then the kind of sacrifices I would have to make for acting, I really don't know if I would have gone for it. It monopolises everything and it's a really tough business. You hear 'no' way more than you hear 'yes'. I'd never experienced that in modelling. You have to have thick skin."

Although resigned to the fact that some people will only ever know her as a model, she says that these days more people associate her with acting. "Sometimes I get a text saying, 'Oh my God, I saw you on a cover'. They think it's a miracle and I'm like, 'Dude, were you not here 15 years ago? You would have seen me on every cover.' It's funny. I'm known in so many different contexts. I like that. I don't like being stuck in a box."

One of the benefits of turning 40, she says, is that she no longer cares what anyone thinks. "I can do whatever I want. I don't feel I have to prove anything to anyone anymore. I could start singing if I want - which won't happen because I'm terrible."

And, she professes, she is now the happiest she has ever been. "In the last decade I have really grown to be the person I am today. I finally understand who I am." And who is she? "Who am I?" she asks with a burst of laughter. "I'm a work in progress, that's for sure."

As published in The Telegraph May 2014