When she was 11, Ms. Lipa and her family moved to Pristina, the capital of Kosovo. But Ms. Lipa wanted to be a pop singer, and at 15 she persuaded her parents to let her return to London. There she started uploading performances to YouTube, starting with cover versions of songs by Christina Aguilera, Joss Stone and others. “You should check out my covers,” she would tell anyone with music connections, resulting in local gigs and demo sessions.

By 2012, the 17-year-old Ms. Lipa was also posting songs she had written on her SoundCloud page. She is still a busy, constant presence on social media, often responding directly to fans. “I’m a bit obsessed with social media because I’ve always been involved with it,” she said. “I just do it all on my own.”

To earn money in London, Ms. Lipa also tried modeling, until her agency insisted that she had to lose weight. “It really messed up my body confidence, because I was so young,” she said. But the experience eventually resulted in a sassy boast of a song, “Blow Your Mind (Mwah).” The idea was “to show everybody to learn to love yourself every day a little bit more,” she said.

Ms. Lipa is a flamboyant dresser; she came to the interview wearing a choker, a baggy yellow cropped-top shirt with waves and the sun sketched on it, high-waisted denim jeans, and “the craziest” fluffy green and orange jacket that made her look, she said, “like the Honey Monster mixed with a tropical bird,” referring to the character from an English breakfast cereal. But modeling left her reluctant to trade on her looks. “I would like to think that my voice is my best feature,” she said. “I want something more like a sonic image — that someone hears it on the radio and hears my voice and thinks, instantly, that it’s me. That’s more important to me than anything else.”

Eventually, her music reached Lana Del Rey’s manager Ben Mawson, and in 2015 Ms. Lipa was signed to Warner Bros. Records. A synth-pop song she quietly released online in 2015, “Be the One,” was unexpectedly picked up by radio stations in Germany and then across Europe; it now has 125 million Spotify streams. Ms. Lipa, meanwhile, was assembling the rest of an album, collaborating in studios across continents with musicians including Chris Martin of Coldplay, with whom she wrote a ballad called “Homesick.”

Her immediate future is mapped out: touring for the rest of the year followed by a break for songwriting in early 2018. “I’m ready to write about the next chapter,” she said. “By shielding myself through music I’ve been able to create this overly confident persona that can say anything and is not afraid of it. It’s made me feel empowered, and from the songs I’ve released, the fans have come back and told me that they feel empowered by it. If I’m able to use music as a shield, I’ll just keep doing that.”