To say that Hailee Steinfeld is taking a leisurely approach to her first album would be an understatement. Since her first single, Love Myself, came out in August 2015, followed by an EP, Haiz, a couple of months later, fans of the singer have been so desperate for her to release a full-length that they’ve taken to making banners to wave in her direction at live performances. “Hailee, where’s the album??” read a succinct plea at the Capital Summertime Ball at Wembley stadium in June, where Steinfeld was re-creating her spot on the huge 2016 single Starving, featuring Grey and Zedd. “They’re so patient!” says the 20-year-old the following day. “I’m working on the music, and I’m just getting it in the perfect place for them to hear it.” What’s taking so long? “Well, I’m sort of out of the game when I make movies, which is a big reason that it takes me a while.”

Unusually for a pop star, Steinfeld came to singing fame with an Oscar nomination already under her belt – for best supporting actress, at the age of 14, for a brilliant turn in the Coen brothers’ True Grit. Six years on, she has pivoted in a different direction: despite a return to critical acclaim in the 2016 coming-of-age movie The Edge of Seventeen, she is mostly starring in teen-leaning blockbusters such as Pitch Perfect 2 and the forthcoming Transformers spin-off Bumblebee.

Facebook Twitter Pinterest Watch the video for Hailee Steinfeld: Most Girls

She is the kind of famous that means her bodyguard paces up and down outside the room while we talk; tabloids write about her as if every outfit were a showcase for “flaunting” her legs or her abs. She has had to deny she’s dating Justin Bieber. She’s mates with Taylor Swift. She is the kind of famous, then, that means she understands how anything she says that deviates from the path of polite platitudes may be blown out of all proportion. And so she is polite, and grateful for every opportunity, and points to the hard work of people behind the scenes of music and movies, and is ever so nice, and a bit reserved.

Her current single, Most Girls, is a tropical house banger with an intriguing premise, which the video makes plain. A handsome model type tells her she’s not like most girls. Instead of swooning at the sight of his chiselled jaw, she looks disappointed in him and does a runner. “I felt that we’ve been accepting the compliment ‘You’re not like most girls’ for a very long time. I have. I feel like there’s been this golden standard or rule that in order to be special you have to be different to other women,” she explains. You could say that it’s empowerment pop. It’s about being happy in your own skin, rather than simpering to a boy’s idea that you’re only worthwhile because other girls aren’t. “I think this generation of women is more than ever banding together and really lifting each other up, and I think girls and guys are really starting to think that way as well,” she says.

Still, when the video came out, that’s not exactly what the focus was on. “Here I am singing this song about how most girls are beautiful, strong, independent, have so much to offer. And the headlines out of that were: ‘Hailee tries on a bunch of wigs, shows off her midriff,’ or whatever. That’s not what I’m trying to say.”

Facebook Twitter Pinterest ‘It wasn’t, here I am as an actor, now I’m releasing music. It was like: here is something I also really love to do’ … Hailee Steinfeld Photograph: Alicia Canter/The Guardian

Steinfeld grew up in California and, surrounded by a family of music lovers, she has wanted to be a singer for as long as she can remember. She is at pains to make clear that she’s not an actor-turned-singer; that both careers started at the same time, it’s just that one took off more quickly. “So the music became more of a side-project over the years, and I would write and record, and I would record covers, just so that I could get the feel of being in the studio. Pitch Perfect 2 [which came out in 2015] was what I used as the perfect bridge into making music, because it felt like it made sense. It wasn’t necessarily random in terms of: here I am as an actor, now I’m releasing music. It was like: here is something I also really love to do.”

That first single, Love Myself, sowed the seeds for Steinfeld’s particular brand of girls-together housey-pop, though its big chant-led chorus about not needing anybody else was deliberately open to another level of meaning, with Vice’s music channel Noisey labelling it a “mastur-banger”. “Ah! Nice! Ha ha ha!” she says, raising her eyebrows. It was a no-brainer that it would be the first single, particularly after the famed pop producer Max Martin appeared at the studio unexpectedly and ended up playing percussion on it. “That was a surreal moment. It was everything I wanted for a first single. It was bold. It was a reminder to myself how much self-love and self-confidence means and how important that is. I was about to perform the song on a talkshow, I was nervous as heck, and there I was singing, ‘I love myself’, and that’s the bottom line.”

It may surprise people to know that she needs the reminder. “Sure. I absolutely do. More so than people would think. I feel like it’s just as easy for me as it is for my friends in high school and college and at their jobs to get wrapped up in our ways of finding validation.” She means scrolling through Instagram or Facebook, say, and feeling like you’re missing out, or that you’ll never measure up. “It’s very easy and sort of scary at times,” she admits, but says people still come up to her and tell her that song helped them, and that that’s what matters.

Facebook Twitter Pinterest Watch the video for Hailee Steinfeld: Starving

Steinfeld’s initiation into the world of pop came via an appearance in her friend Taylor Swift’s girl-gang video for Bad Blood in 2015. Is she officially in the squad? She laughs, a little wearily. “It’s so funny, I met Taylor before that was ever a thing. Being in that video was so awesome, all the women in that video are great. The best part was, we were doing it and it was just sort of, as crazy as this sounds, a day with friends. And then we saw it all together at an awards show on this massive screen and it was just unbelievable.” Was she aware of a backlash at the time, that suggested it was less about friendship, and more about showing off an exclusive clique? There is the faintest crackle of tension in the air, a slight stiffening of posture, but her smile remains fixed. “Sure. Mmm. Right. I think everybody’s always going to have their interpretation of something. That might be more of a question for her than it is for me. She asked me to be part of it and I felt honoured. I loved being part of it; it was great and the video was beautifully done.”

Steinfeld is about to start work on Bumblebee, and Pitch Perfect 3 is due out at the end of the year. That means there is still no answer for the fan in the crowd asking for an album, but she says she does have a new song coming out soon. “I’m lining them up as we speak. The next song is something I feel very strongly about and excited for.” Tell us more. “Well, what can I tell you? It’s a collaboration. There are a couple of people on it that I really love and consider great friends. Unexpected, though. I don’t think anyone will see that coming.”