How long should a supermodeltake to spring back into shape after having a baby? For Erin O’Connor, who gave birth to her first child, by her longtime partner, Steve Gibson, in July 2014, it was a good six months. In a way, she wished it had taken longer. “Having been a walking right angle most of my life, I felt blessed when I first got these five new bumps [baby bump, bosoms and bottom cheeks] and I wasn’tthat willing to let them go. Being candid here, I was lucky that breastfeeding made my body decide to hold onto that every last pound.” The regally limbed O’Connor, 37, dressed in a long DSquared2 floral skirt, has just swept into the Café Royal. With her is her new(ish) agent, Jonathan. As he makes to sit down with us, she wonders — thank you, Erin! — whether he might be more comfortable at the next table. No, he wants to be right here with us, a decision he may regret, because for the next 30 minutes we talk of nothing but babies and her one- year-old son, Albert. “Honestly,” she jokes, “if I weren’t his mother, I’d definitely be his stalker.”

    “One of the best models in the world” — that is how Karl Lagerfeld describes O’Connor. Or as Jean-Paul Gaultier, another longtime fan, once pronounced: “She is quite like art. She is like theatre.”

    Gaultier is right. Beyond that pale, pale skin and noble Roman profile, she is way more than a model in her role as former vice-chairwoman of the British Fashion Council and as co- founder of All Walks Beyond the Catwalk, which campaigns for greater “individuality and diversity” among models.

The girl who was first scouted at the Birmingham Clothes Show in 1995 is back on the catwalk at an age when most models have long since retired, including walking for Giles Deacon at London Fashion Week last month, as well as for Michael Kors and Marc Jacobs in New York. “Can you imagine not working for someone for 10 years and then there they are, virtually on your doorstep?” she says. “But Marc hunted me down. That’s how it works with him.” In July, she graced the pages of Italian Vogue, shot by Steven Meisel, and in the past few months there is hardly a fashion brand that hasn’t ensured her presence at its parties and dinners.

     Born in Walsall, the middle of three girls, and brought up by her mum and furnaceman dad on a council estate, O’Connor, like her son, was tall from the moment she came out of the womb. By the age of 16, she was 6ft, with dark brown hair down to her waist, earning her the moniker Morticia. Though shy “with a tendency toward OCD” (she says a sense of order has always been crucial to her wellbeing), she was also a bit of a performer. “Just the way I deflected the extremity of my body was to make other people laugh,” she explains, the only trace of Midlands being the flatness of her As. “It was like, OK, you’re going to look? Well then, I’m going to put on a show.”

    That sense of performance — she spent 10 years from early childhood to late adolescence studying ballet — has always infused her craft. Perhaps, had she not been a model, she might have been an actress. I’m thinking of all the great characters she has played on the runway, Pete Doherty for Gaultier and the lunatic- asylum lady for McQueen (remember that razor-clam ballgown she wore in 2001, clawing at the glass walls?). Didn’t she so perfectly Modelling is a brilliant medium for me. it’s almost a sanctioned loss of control evoke Diana Vreeland for Jacobs’s AW15 Garden of Hell show in spring?

    “Oh God,” she snorts, “I would be a phenomenally bad actress, because all my gestures are grand and quite static. I miss that subtlety needed for great acting. Modelling is a brilliant medium for me. It’s almost a sanctioned loss of control, these short bursts of letting go, this temporary fleeting, which I mean every moment of when I’m out there, or in front of the camera — playing this persona who is somewhere between you and the client’s expectation — but then I come off and I’m fine. I don’t need it any more.”

    This capacity to think of modelling almost as meditation on the move, or at least her capacity to compartmentalise, is probably what has kept her sane in the insane world of fashion. “Yup, manufactured poise,” she says. “That’s definitely what I have learnt over the years.”

    Not that there haven’t been times when that poise has been slightly toppled. Like the fitting in Paris when a designer actually slapped her bottom and told her she was too big for a pair of trousers. Hurrah, Erin said, the trousers needed to be made bigger then, and walked out. “Look,” she says, “modelling is a tactile business. But that was inappropriate and something that should never be said to anybody. At that moment it didn’t matter what they thought. It mattered what I thought of myself. I mean, I can part ways with people, but I’m always going to be with myself, aren’t I?”       A self-help book, Life Lessons with Erin — that, surely, is what this magnificently sensible, articulate supermodel should be doing next. And indeed something along those lines, a sort of memoir of her modelling days, is in the pipeline. “I mean, let’s hope there’s enough content to put in a book,” she says. “I’ve always wanted to identify with a wider audience, both in fashion and beyond, and this would be a way of doing it.” She says social media, and Instagram in particular, has allowed her, for the first time, to be in charge of her own image, “to load the content and tell the stories I want to convey”. (She has 31,000 followers on Instagram and posts a mix of quirky pictures and witty quotes such as: “Hey, sorry I’m late, I didn’t want to come.”)

     So it’s all part of the big plan, then, to be a brand? “Oh God,” she snorts again. “A brand!” And then, after considering this carefully, says: “I’ve always represented other brands, so to take ownership of myself as a woman, and work with brands on a collaborative basis — that feels like the right positioning. Finally.”

     And how does she see herself in 10 years’ time, when she is three years shy of 50? Will she still model full-time? “I love a challenge,” she says. “I love my career and I can only continue in this direction, which is to be how I am. Now that I know who that person is.“

    Another passion is weightlifting (yes, that’s how this fragile orchid got back in shape — pumping iron) and collecting vintage furniture, much of which is in evidence at the family home in Camberwell, south London. Think faux- leopard upholstery and an iron-bottomed free- standing bath — all very far from the “polite, beige” decor and double-glazed windows of her 1970s childhood. “I remember everything being quite new,” she says of the home she grew up in. “I think that’s why I now love things that belonged to people before.”

    With her fortune — £12m at the last count — O’Connor can indulge in all the vintage furniture she wants, but would she consider herself extravagant? “If you saw my Ocado shop, maybe you’d think that, but let’s see. Hmmm. Extravagant? If you’ve worked so damn hard your whole life, you want tangible things to represent that. It’s definitely OK to be happy and have nice things. ”

    Which doesn’t bring us at all to Gibson, an Irish businessman specialising in tech start- ups. Although O’Connor has always been quite secretive about him, one gets the impression that he has broad enough shoulders to play the Mr O’Connor role with grace. Apparently he is also a great daddy. “I guess Albert loves a wrestle with his dad and a cuddle with his mum. But yes, of course he changes nappies.”

    Back to babies then, sigh, and how sweet it was taking all that time out, and sitting for three hours in front of the TV and watching back-to-back episodes of Come Dine with Me while breastfeeding. And how, yes, she wants another (“Well, Albert needs a pal”), but maybe not just yet, because it’s hard to drag yourself back from that world into this one. “I remember one of my first jobs back was walking for Giles,” she says, “and although I was triumphant to be working and feeding at the same time, as I walked, I missed that feeling of gripping the pram. It had become my roving security blanket and without it I felt handicapped.

    “But I knew it was a balancing act, and I knew I could do both. A defining moment was when I got these two emails in succession, one from Mothercare and one from Marc [Jacobs]. I looked at them listed on my laptop and thought, ‘That is the story of my new life.’ ”