She has an army of A-list fans — not to mention a new husband and baby in tow. Now shoe designer Tabitha Simmons is plotting her next steps...

Lunchtime at La Mercerie, a chic brasserie in the heart of New York’s Soho, and Tabitha Simmons is sharing tales from the domestic front line.

Hers are more glamorous than most. Take this anecdote about juggling a career as one of the most in-demand shoe designers in Manhattan and quality time with her children Dylan, 12, Elliot, 14, and Violet, seven months: "I like to be there before the boys get back from school and be with them for dinner. Even if I’m going out. So one time I found myself whipping up cauliflower cheese in a ball gown — full-on Dolce & Gabbana, totally normal!"

Then there’s her prodigious shoe collection, which she estimates to be ‘in the thousands’. "My nanny is always like, 'Every cupboard I open is shoes, shoes, shoes!' They’re in the office, they’re in every closet, they’re in drawers. I’m going to have to start doing a proper archive..."

Simmons speaks self-mockingly, which is a comfort; she is one of fashion’s best-connected women. She counts Tory Burch, Lily Aldridge and Alexa Chung as friends, and Jennifer Aniston, Gigi Hadid and the Duchess of Sussex as fans. Formerly married to legendary fashion photographer Craig McDean, with whom she had Dylan and Elliot, she married Violet’s father, Standard Oil heir (and former husband of New York socialite Tinsley Mortimer) Robert Livingston ‘Topper’ Mortimer, in a fairytale cathedral wedding this June. Current projects include a jewellery capsule for Atelier Swarovski and a clothing line for cool-girl fashion brand, Equipment.

Her shoes are the kooky side of elegant — classic styles with quirky embellishment — and built for comfort and to last, which is what made her a go-to brand for brides (who can customise insoles with an embroidered inscription, as Poppy Delevingne did). "I wear all my designs," Simmons says. "I want to make sure the quality is exceptional, so you’re not like" — she winces and grabs her foot for effect — "'Ow!' I really try and bear in mind that women have busy lives, and they want something that’s fashionable, but not necessarily something crazy."

Born and raised in rural Cambridgeshire, Simmons studied film and set design at Kingston University and worked as a weekend shop girl at Joseph. There she discovered designers such as Alaïa, Dolce & Gabbana and Prada — and it is where she was discovered by a modelling scout. "I was a terrible, terrible model," Simmons smiles. "Karen Elson, my best friend, is a genius model and I understand why she’s been at the top of her game for so many years, but I was very awkward and not comfortable in my skin."

Encouraged by Edward Enninful, then fashion director of i-D, Simmons moved into styling, landing work with Dazed & Confused and forging an enduring friendship with Jefferson Hack, who later helped her get her footwear line off the ground. As her styling career gained steam, she landed a contract with Calvin Klein and moved to New York, where Elson introduced her to McDean. Until their split in 2013 the two were a fashion power couple, collaborating on shoots and renovating an airy Manhattan townhouse that appeared in countless glossy magazines. While styling a few runway shows for Alexander McQueen she had a brainwave about footwear.

"You can wear the same dress, but whether you’re wearing a platform, a kitten heel or a sneaker, it can look totally different," she says. Her line, launched in 2009, was a hit straight out of the gate, winning awards (including a British Fashion Awards’ Emerging Talent prize in 2011) and generating frenzied celebrity fandom. And yet, she confides: "I still feel like I’m sitting at the kiddie table."

Despite the demands of her brand, the extra hours required by the Swarovski tie-up or her ongoing collaboration with Colombian designer Johanna Ortiz, Simmons still works as a contributing editor for American Vogue and zips around the world styling ready-to-wear and Alta Moda for Dolce & Gabbana. "Every day I wake up and my day is different," she says. "I’m travelling, going to appointments, doing presentations, organising a shoot, flying to Milan to work with Dolce..." When it all gets to be too much, she confesses, "I play Candy Crush and watch bad reality shows. That’s what I do to shut off my brain because it’s constantly buzzing."

Simmons and Mortimer met ‘many, many moons ago’ in the Hamptons but didn’t see each other for years until "he saw me one night at the Firehouse in London, but he didn’t come up to me. He felt like it wasn’t the right time and he didn’t want to blow it. But he got in touch afterwards and asked me to go for a coffee." She flushes as she tells the story. "I think it’s fate. When the time is right, it just happens. I believe that now."

They now have homes in Manhattan and the Hamptons. Violet wakes Simmons up at all hours ("she went off at 5.30 this morning like an alarm clock, my little chicken"). The boys first greeted the new arrival "like two great danes who were terrified of a chihuahua" but are now thrilled to have a sister.

Though she has been based in the US for more than a decade, Simmons’ heart still belongs to England. "I miss Sunday roasts and pub lunches and TV soap operas — things I’d never thought I’d miss," she says. When she returns to London she catches up with friends such as stylist and Love editor-in-chief Katie Grand, visits her favourite restaurant, Isabel, in Mayfair, and does a little shopping. "John Lewis is always a port of call," she says. "I just love it. There’s just nothing like it in America."

Her British roots inspire her designs, with lace-up boots and floral flourishes giving a sexy twist on prim Victoriana. "That’s something I bear in mind with every collection — keeping that Englishness and that femininity. I’ll go travelling around the world and find amazing inspiration. Like I’ll see a chandelier and think: 'That could be a great shoe.'"

Simmons will reach an even larger audience when her collaboration with Equipment hits stores in October. And then? "I just want to carry on growing," she says, toying with the gold necklaces inscribed with her children’s names. "People say, 'I see your shoes everywhere,' and that’s exciting, but I’m always thinking, 'How can I improve?' There’s so much more to do. I’m always trying to move forward."