British singer Foxes has gone from unknown to Grammy winner and red-carpet regular in less than a year

The young Southampton pop newcomer known by the nomme de gig Foxes didn't expect to win a Grammy. Of course she didn't. For one thing, if Louisa Rose Allen had thought she might beat the all-conquering Calvin Harris to the Best Dance Recording, she wouldn't have nipped out for a pint with electro duo Disclosure and Brits Critics' Choice winner Sam Smith halfway through January's ceremony.

For another, the 24-year-old was, say it again, a brand new artist, scantly known in the US and with barely one full UK single to her name.

As it was, when Foxes' name was called from the podium at the 56th Grammy Awards in Los Angeles on 26 January, she had not long scraped back into the auditorium, and just remembered to give a shout-out to the key person on her non-existent thank-you speech: her mum. "And for some reason I decided to tell everyone in the room, and everyone on telly, that I had chewing gum in my mouth," Foxes reflects with a mortified sigh. "It's so bad. I just vomit words."

This bright, personable young woman shrugs and returns her attention to demolishing the blueberry muffin she's having for breakfast. We are sitting in a canal-side café near her flat in Dalston, east London. Soon, by chance, her big (and heavily pregnant) sister will enter the same café – she also lives round here, as does their mum. (Their brother lives in Amsterdam; Foxes has no contact with her dad.) Meanwhile, much to her mortification, I try to Google her acceptance speech.

The backstory, then, to Foxes' out-of-nowhere success at the world's most prestigious music awards: "About 18 months ago", young dance producer Zedd was searching for a singer for a new track. After "looking for ages", the LA-based German (who has also worked with Lady Gaga) heard Foxes' "Youth"; the lyrics were inspired by the artist's single-parent mum – a young-at-heart mother-of-three who followed both her daughters to London to open a second-hand clothes shop, Vintage Upmarket, on Brick Lane.

Although some way off being released as a single, "Youth" was knocking about on the internet. Zedd was impressed. This was the singer he needed for his single "Clarity": clear and soulful, full of personality but no dance diva; powerful without being foghorn.

Foxes admits that at first she was wary – the potential for raver-queen naffness was high. "As much as I really do love elements of dance music, and it's something that has inspired me a lot, the whole EDM thing," she squints, referring to the cheese-whiffed acronym (electronic dance music) that Americans insist on applying to dance music, "isn't something I would want to pin on myself."

But Foxes had done time as a singer- songwriter, and (briefly) at a performing-arts school, and had played her share of open-mic nights in London. She's been signed to her record label for more than two years now, and been hard at work writing and co-writing her debut album, Glorious. She knew that young artists have to explore every opportunity – guest slots on other acts' tunes being one of the best. So she listened to Zedd's track, and thought it was "really beautiful. It wasn't just a dance track; it was in the vein of a lot of my music. It sort of felt like a song that was gonna change the way people perceived dance."

That might be overstating things a little. But "Clarity" is a persuasive and effective stadium-house belter. It was followed by other guest-vocal appearances by Foxes: on the single "Right Here" from the number-one album by fellow Hackney residents Rudimental, on "Just One Yesterday" by American rock band Fall Out Boy. And then, 16 months after its release, it was followed by a Grammy – a surprise achievement that has rocket-powered Foxes' public and social-media profile.

We're meeting 10 days after she landed back in the UK from LA. There's been no time for celebrating for the girl known as Loui to her friends. "I went straight back to work. I mean, if I look at my diary," she says flicking to her iPhone calendar, "I just don't even know what I've been doing. It's day and night now – it's just got very busy…" she exhales, still fatigued by a whole day's worth of regional radio interviews.

This is the midst of awards season: the opening two months of the year studded with film and music bashes aplenty, from the Brits to the Baftas, the Grammys to the Oscars. We talk about what it's like on the ground at one of these events. On the mandatory pre-event red carpet, Foxes was already feeling out of place. "I really felt like I was gonna be told to leave at any point! 'Make way for Beyoncé…'" she recounts in her speedy, bushy-tailed manner. "You just think: what am I doing here? I started getting interviewed by Jack Osbourne. And I thought, 'This is a bit bizarre – I should be interviewing him.'"

It's not a completely fanciful suggestion. In the modern, multi-tasking, starter-star way, Foxes has already been for a meeting with hipper-than-thou media brand Vice about fronting a youth TV show of some stripe for Channel 4. And, as is equally mandatory for young musical stars, she has representation at Premier Models – they look after her for fashion and brand partnerships.

Foxes wore Vivienne Westwood to the Grammys. Shall we Google that, too? "Stop Googling me! I didn't actually like the dress that much," she says, her newbie-naivety trickling through – fashion people are never disloyal, at least not publicly. "On me, anyway," she backtracks.

To paraphrase the biggest viral hit of the last year: what does Foxes say? Why be a musician, and why with that name?

She says she always wanted to be in music – not so much a pop star, more a singer and songwriter. It took her a while to find her footing, though. "I was a bit of a blagger growing up. I went here and there and didn't really know what I wanted to do," she says, copping to long stints working in bars and a year at London's Institute of Contemporary Music Performance.

Earlier on, aged 18, she was accepted into beauty school in Southampton. The day before she was due to start, her big sister called. She knew of Loui's passion for music. She told her to wise up, forget make-up, and come up to London immediately.

"And my mum and I put all my stuff in her car. And this is really cheesy but Mark Ronson's [cover of] "Stop Me" came on the radio. And my mum was like, 'It's a sign! Let's go!' And we drove up to London, and I never looked back! My mum is awesome."

Indeed, that mother-daughter bond in part explains her stage name – a change that was, initially, born of necessity. Just as Emeli Sandé's actual first name is Adele and that was already, as it were, taken, so Foxes' birth appellation is uncannily similar to the full name of another British female star: Lily Rose Allen.

"I just thought, the comparisons are gonna get too much. Then someone said, 'What do you think about Foxes?' And I was like, 'That doesn't make any sense. I don't think it's very good.'"

But it stuck in her head – partly because the first song she'd ever written, aged 13, was called "Like Foxes Do". Sample lyric: "Like what foxes do/ I'll bury underground whilst I wait for you/Make a palace out of trash/ Like foxes do/ I'm the only one for you/ Isn't that what foxes do?" Yes, she concedes with a grin, "I was young and weird and soppy. I used to dedicate diaries to boys I had crushes on. But you do learn…"

She asked her mum what she thought of the name Foxes. She replied: "That's so weird. Last night I had this dream about these foxes running up our street and they were howling and making these beautiful noises. And I woke up thinking, 'God that's like your music…'"

Loui is "very close" to her mum, "and I like that she has that connection. So I thought, 'That feels right, we'll go with it.'"

The irony, of course, being that while Foxes' music is dance-flavoured, big-voiced pop-soul, notably on her super-energetic new single, "Let Go For Tonight", foxes sound like a baby being mangled. "It's horrendous," she agrees. "But the thing is, you know when you get used to a name? Like, Sting is quite a weird name… But also, someone told me yesterday that on Google Images, apparently I'm the first entry – I've taken over actual foxes on the internet," she says with notable pride.

The canidae's loss is London Fashion Week's gain. A week later, I hunt Foxes again – over the five-day style binge, her presence is in hot demand at catwalk shows and presentations by a host of labels: Vivienne Westwood, Topshop, Jonathan Saunders, Miu Miu (which was dressing her for the Elle Style Awards), Mark Fast (who was dressing her for the Brits), and Markus Lupfer (for whom she had compiled a playlist of tunes to mark the unveiling of his new collection).

"I just love her because she's young and energetic," the German-born designer tells me as fashionistas swarm around his Saturday- afternoon show in Covent Garden (we've just missed Natalie Portman and Myleene Klass, apparently). "I'm obsessed by her music. She's got such a good vibe. She's fresh and new and quirky, and I love her image."

After being Instagrammed by fashion bloggers in her new Lupfer outfit – hot-pink sci-fi Barbie, I'm saying – Foxes has to dash. She's squeezing in tour rehearsals before her next awards-season pit stops.

At least this smart young star already has some serious red-carpet experience; at least she already has her own award. Not that Foxes has actually taken possession of her Grammy yet – it's still in America, being engraved.

"I loved Jay-Z's acceptance speech that night!" she beams. The rapper dedicated his award to his and Beyoncé's baby girl: "I want to tell Blue – daddy got a gold sippy cup for you!" Foxes was touched. "I thought that was genius. So when I get mine, I'm gonna give it to my little niece. Just for a bit, though."

'Let Go For Tonight' is out now. Foxes' debut album, 'Glorious' is out on 12 May. Foxes is on tour now; for details: iamfoxes.com