In September 2016, Danielle Bregoli – then 13 years old – flicked her straightened hair over her shoulder and pursed her lips while someone referred to her as the antichrist. Dr Phil, on whose family-counselling TV show she was appearing, was insisting she was not the antichrist her exasperated mother described. So far, so daytime television. But unlike many of the “tearaway teens” stereotyped on shows such as this, Bregoli has grafted the beginnings of a career on to this wobbly scaffolding.

If her name is not familiar, you may be aware of her rap alias, Bhad Bhabie, or “cash me ousside”. That catchphrase – a threat to “take this outside”, aimed at the studio audience that was laughing at her – has since become a meme and, for some, a crude summation of her character. “People have this misconception that I’m going to beat them up when I meet them,” the 15-year-old says now. “But it’s like … no. Just ’cause I stand up for myself and I’m honest, that doesn’t mean I’m going to beat people up all the time.”

Hearing her speak, Bregoli could be anything from a 12-year-old – when we first meet, she is screeching at her manager about how her hair makes her look homeless – to a jaded 42-year-old, sighing world-wearily. But she is most certainly a child, one introduced to the world on TV thanks to her mother’s distress about her criminal adolescent behaviour (car theft, knife threats, what Bregoli describes as a proximity to drug dealers).

All the hits ... the video for Hi Bich/Whachu Know has had more than 100m views on YouTube.

Her foray into rap has led to a major-label record deal, a handful of buzzy singles and a US and European tour. Her tracks are often brilliant in their withering focus: Hi Bich bounces along on a belly-shaking trap beat, punctuated by an earworming shopping-list chorus: “White Js, white Porsche / White wrist, white horse / Hi, bitch / Hi, bitch / Hi, bitch / Hi, bitch.” Nearly 15 million people follow her on Instagram. At the centre of this is a girl who oscillates between two personas: the remnants of the primary-school-aged child photographed cheek to cheek with her single mum; and the potty-mouthed teen who, on returning to Dr Phil’s sofa last year, told him: “You were nothin’ before I came on this show.”

In many ways, Bregoli is a regular kid. In an east London hotel room, she sits curled up in a chair in front of her half-eaten macaroni and cheese and rolls her eyes while talking about boys. She remembers how her close friends, 21-year-old YouTuber model twins Elijah and Isaac Bell, had tried to get her chatting to someone her age, after most of her female friendships fell apart.

“And they were like: ‘OK, well, how about this person?’ He was 16. So I start texting him and he was so corny. Saying: ‘What do you wanna talk about?’ What? Is this fourth grade? And then he was all: ‘Do you send pictures?’” – meaning provocative selfies. “Nope, goodbye! Conversation ended and you’re blocked.” She pauses. “And it was like, all right, I don’t have female friends or guy friends or a boyfriend. Well, I’m screwed.” She scoffs. “Pfft. Teen boys are a huge mess.”

The day we meet, she is easing into downtime between shows and has shed her usual armour of false lashes and acrylic nail extensions. Barefaced, she throws back her head and laughs one second, then mock-scowls and picks at the rips in her jeans the next. Overall, she comes across as a sweet girl, if perhaps one who may look back in 10 years and cringe at quotes she gave to journalists, some twice her age – or wonder why those adults seemed to want to provoke her.

In the spotlight ... Bhad Bhabie.

Her words tumble over themselves when she is excited, as though her mouth is playing catchup to a mind moving at a few hundred miles a minute. Case in point: how jaded she sounds when talking about the mechanics of the music business, with less than a year’s experience of it. She launches into several big-name stars, claiming that if people think they wrote their big hits “they’re out of their fucking minds. Half these motherfuckers don’t write shit. And if I did have a ghostwriter … what’s the problem?”

If she sounds defensive, that is likely because plenty of observers online – in hip-hop and entertainment more broadly – saw her music as a joke, even as it was becoming enormously popular. Atlantic signed Bregoli in September 2017, after releasing her debut single, These Heaux, in late August. Hi Bich followed and its joint video with her track Whachu Know has racked up more than 100m views on YouTube. All of Bregoli’s singles so far jostle her forward as one of the few young women associated with the US crop of lyrically simplistic, goofy and sometimes arguably violent SoundCloud rappers.

Just ​’cause I stand up for myself and I’m honest, that doesn’t mean I’m going to beat people up all the time

She has cultivated friendships with labelmates Lil Skies and YoungBoy Never Broke Again, as well as red-braided collaborator Lil Yachty (he appears on 2018’s Gucci Flip Flops, the title rhymed with “hit your bitch in my socks”). She understands that she is an anomaly in their world, a white child seeming to attach herself to a historically black genre. Her whiteness gives her the privilege of a second chance at being “good” and jars with her drawling Florida-plus-Brooklyn accent. But the sweary brashness is not an act, she insists. “I’m just me, all the time. People think: ‘She must be an innocent little white girl when she’s not performing or making videos.’ But no, I’m me all year round, 24/7. There’s a softer and harder person in everyone, depending on the time. I’m not gonna walk in a church and say: ‘Wassup bitches?’ No.” She pauses for effect. “I might say it, but it’s gonna be quiet.”

Raised in south Florida’s Boynton Beach area, Bregoli says she was a difficult infant. “I had this little Barbie Jeep and used to flick off the nothing behind me because I’d watch my mum do it in her car. I’ve always been a little brat annoying child. I think I’m always gonna be a nightmare, for sure.” Even so, she was friendly with a couple of girls as a pre-teen, around the time when she shared a bed with her mother, who was living with a cancer diagnosis.

“And that’s where my life kinda went ...” She motions the swift downward path of a falling jet, blowing a raspberry with her lips. Bregoli had fallen in with one young girl who “got me into selling drugs and doing really stupid shit. I really cared about her, I believed she was a good person, but … she wasn’t.” Now Bregoli sees the time she and her ex-friend spent off the rails as a part of growing up.

‘I’m me all year round, 24/7’... on stage at the Roxy theatre in Los Angeles during her 2018 US tour. Photograph: Scott Dudelson/Getty Images

“It’s not, like, a phase,” she says, tugging at her high ponytail. “I don’t think you call stealing cars and selling drugs a phase.” She chuckles drily. “I think that’s more of … ‘I’m bored, let me figure out something to do.’ I would still do that now if I wanted to, but I don’t. If I’m handed a fucking music career, yeah, I’m gonna stop doing dumb shit and do that instead.”

Since being bundled on to a troubled-teen rehabilitation programme, per Dr Phil’s orders, she has not always avoided conflict. She was caught in an altercation on the flight home after her second Dr Phil appearance and in another on the street involving two social media “personalities”, aged nine and 18. She has also uploaded caustic and witty YouTube videos responding to other YouTubers reacting to her music videos. Does she still feel underestimated? “Yes, 100%. What bothers me is when people listen to my music and they’re like: ‘This is low-key good.’ Why does it have to be low-key good? Why can’t it just be fire? I don’t understand. It is what it is – just say it’s cool.”

Given how quickly she fell into rap, I ask whether she plans to stick with music for the long haul. She slows down, sounding well aware of how swiftly 15 minutes of meme-induced fame can slip through your fingers. “I definitely do wanna keep doing it – if it were up to me. But if other opportunities come along the way, then, you know …” What about the reality show rumours? She won’t commit. “If I do a reality show, it’d have to be around music. I started something, so I’m gonna … well, not finish it, actually – I’m gonna keep doing it.”