'Taste changes but style doesn’t'

She is also very “discreet” when it comes to talking about Meghan Markle wearing her clothes. Or not talking about it, as the case may be. She tells me that Goat “has been dressing high profile clients for many years, but we do it discreetly.”

The high profile clients include Victoria Beckham, Lana del Ray and Gwyneth Paltrow, as well as another royal fashionista, the Duchess of Cambridge.

“We don’t seek the publicity,” says Lewis, “but it’s very gratifying for my whole team; it’s the highest accolade.”

I have to admit I was a bit apprehensive before this interview. After an initial email from Goat’s publicists asking if we’d like to interview Lewis following the success of Meghan’s dress, it all went a bit cloak and dagger. A date couldn’t be agreed upon until questions were sent over, then the location for the interview was kept secret until the evening before we were due to meet, and talking about that dress was off the record. It was unusual and, if I’m honest, a bit wearying. Also worrying: who was this ogre I was going to meet?

I’m led through the labyrinthine staircases of her office, and I’m greeted with a big smile. It gets bigger when her assistant arrives with a cup of coffee. “Finally!” she exhales, “fuel”.

Lewis is no ogre, I realise, but she’s got phenomenal drive and determination, which can be a little scary. She started Goat in 2001 as a solo venture, although she had no formal training in design.

“I wanted to work in the art market initially, but went to work with a designer by chance and had a quite a good intro to the business,” she explains. “I saw how fashion shows were put together from start to finish, with all the issues that come during the course of the collection, which is invaluable really.”

This inspired Lewis to jump in at the deep end and launch her own collection. This was built around clothes “you would turn to again and again, unsung heroes” including a perfect crewneck, a beautifully cut pair of trousers, a couple of “really slick, sharp coats”.

How does a 26-year-old from Hampstead with no fashion training know where to start with her first collection of clothes? “It was just my taste, what I like to wear. I think to be successful and to continue doing something successfully and in a relevant way it still has to be what you like. Taste changes but your style doesn’t.

“You start out doing something you love don’t you? You don’t design something you don’t like, so I started out with something that made sense to me.”

Lewis is very expressive, using her arms and hands to gesticulate, especially when she is stuck for a word. Although it strikes me that her answers are, if not rehearsed, then well-known to her. This is her baby. She built the company from scratch and is very insistent about how hard she worked, the challenges she faced down and the sacrifices she made to get to this point.

“It was hard graft and in the beginning that can be soul-destroying. You need to be courageous.”

She took her capsule collection out to buyers and boutiques herself. “You’re being judged, so it’s easy to take on board what the buyers say and deviate from what you initially set out to do. It’s difficult to maintain your integrity.” But she stayed strong and found some independent boutiques that were happy to take a punt on her collection.

“I look back and admire my younger self for not giving up.”

Lewis still employs two of her first four hires, taken on only when she was pregnant with her first child. She also designs and draws everything for every collection, although her team has now grown to 20 people.

She had a young baby and young business at the same time —“I juggled being pregnant with a business in its infancy and a growing family — my business and family have grown in tandem!”

But she says: “I believe in balance, like to think I’ve achieved success while maintaining family, friends, work. I don’t believe in sacrificing one for the other — I believe you can have it all.” Having it all includes three children, two girls and boy aged 13, 10 and seven respectively, with her Israeli husband with whom she lives in Bayswater.

There have been sacrifices however. Lewis had no maternity leave with any of her children (“I had help, I’m not going to lie”) but her family have proved as much of an inspiration for her business as a welcome balance.

Goat recently launched Kid by Goat, a kids’ collection. This again is a capsule collection, born from a need to dress her daughter for a barmitzvah.

“I wanted to find a middle ground for event dressing. Not to solely rely on retailers like Topshop with a sometime overtly mature or trendy aesthetic. She wears her Converse with a Goat dress. A happy compromise.”

So Lewis made a dress from scratch — a one-of-a-kind, mini version of Goat’s cult Lola dress in a bright cobalt blue. Her daughter wore it with navy Converses and the mother-daughter duo were the talk of the simchah. After comments from other mothers Lewis decided to launch Kid, which features the Mini Lola, for £180. “I thought about the price point quite carefully. If you go to a high-end kids’ shop like Bonpoint, [that price] is what you’re looking at.”

But it’s worth it, she says, pointing out that “we all” have photos from when we were children which make you you bite your lip when you see it, horrified by what your mother dressed you in. She doesn’t want that for her children. who all “have different personalities and I try to celebrate that; I don’t dress them the same, but dressing a teenager — it’s a whole new world!”

The proof that her experiment was successful is — apart from the sales of the new collection, which launched this season — that her daughter wears her Lola “whenever she goes somewhere nice”.

Not everything is as easy a success as this however. “I say this very openly because I think it’s important to learn from it,” she says, earnestly: “every season, in every collection, there are pieces that don’t work. Sometimes I find I’ve got a happy accident and it turns out to be a winner. Sometimes — and it’s always the way actually — the piece I think is going to be an absolute slam dunk isn’t and I am always slightly flummoxed.” But she doesn’t stay knocked down for long. “Part of being able to stay on top of this business and to stay in the game is to take these wins and losses. I’m not offended, I learn from it.”

“I’m designing for a broad selection of women,” she notes, “so I can’t just design for myself anymore, I can’t be selfish.” Nonetheless she designs with real women in mind. “There’s a lot of vanity in fashion, I’ve got my press to think about and editorial, but then I have to think ‘can you wear a bra with that?’. You have to think about function and comfort. If you forgo those key check points — the nuts and bolts of getting dressed — you’re letting your customer down. It really matters.

“That’s the difference between starting your business when you’re younger and the experience I’ve gained down this long journey. I know who I’m designing for.”

Her customers are loyal and they are “anybody from a 27-year-old to an 80 year old” and they buy online, at Goat’s flagship store on Conduit Street and in select boutiques. Everything comes in size six to 16 and she loves that her clothes look different on different body shapes

“I wear a lot of Goat,” Lewis admits, unsurprisingly. But today’s outfit isn’t her own: “I don’t make jeans!” she laughs and presumably she shops elsewhere when hanging out in Tel Aviv with her family. They have a home in Israel and, like many Israelis, while not “religiously observant in the traditional sense we participate; I have a strong Jewish identity.”

And finally: where does the name come from? Lewis laughs. Goat began life as a cashmere range, and that's how the name came about.

And now it has taken on its own identity. “It is quite an odd name but, yeah – I still really like it.”

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