Aged just 20, she has made a name for herself by not being afraid to publicly lead the charge as a vibrant and socially engaged young voice for the industry’s younger generation.

“I’m outspoken and I’m not afraid to speak my mind, even if it’s controversial,” Moretz tells Stellar.

“It feels like I’m not doing what’s right in the world if I don’t educate myself. If it’s important, I’ll speak about it. I don’t think about whether that hurts my career or not.”

Since breaking out as the lead in the foul-mouthed, anti-superhero movie Kick-Ass in 2010 — filmed when she was 13 — Moretz has arguably drawn more attention for her honesty than she has for her CV, which is peppered with big Hollywood epics (Hugo), standard horror fare (remakes of The Amityville Horror and Carrie) and comedies on both the big screen (Neighbors 2: Sorority Rising) and small (30 Rock).

Despite her youth, she has weighed in bluntly on everything from body-shaming (earlier this year she revealed a male co-star once told her he wouldn’t date her because she was “too big”) and LGBTQ rights (she has two gay brothers) to politics (she campaigned for Hillary Clinton last year).

“I do feel a duty to speak out on these things,” Moretz says. “Of course I want to turn my phone off and run away, and stick my head in the sand. But you can’t; you have to do something.”

When Stellar meets the actor, she is attending a rain-drenched party at New York’s High Line (an abandoned freight train track turned into an elevated park) hosted by American luxury brand Coach, for which she is the face of their fragrance. And Moretz, in a light floral dress designed by the label, is shivering.

“Not the best dress for the weather,” Moretz grimaces. As if out of nowhere, a headset-wearing assistant appears to proffer an umbrella and a blanket.

Moretz cocoons herself inside the wrap and is shepherded to drier surrounds. She smiles before grimly adding, “Covering myself in a blanket can only help the way I look right now.”

Coach tapped Moretz to be one of its ambassadors in 2015, recognising her as a young celebrity who also wields considerable clout.

“Chloë has a sense of optimism that I feel sums up Coach,” the brand’s creative director Stuart Vevers tells Stellar. “Her ease and effortless style feel relevant. And she’s a bit of a rebel — we like that.”

Moretz thinks young women and teenagers gravitate to her because “it’s relevant right now to have a point of view — and mine isn’t forced, in a sense.

“Young women, in particular, are able to see that it’s not an act and it’s not a show. I just have a lot of thoughts and ideas that I decide to really push out.”

She has at times taken grief for doing this; when she criticised Kim Kardashian’s near-nude selfies as “voyeuristic” and “not about body confidence”, the reality star fired back. Moretz is not interested in rehashing their stoush, saying she is fed up with “woman-on-woman hate”. Instead she says she despairs when young women refuse to align themselves with feminism.

“You want equal rights? You’re a feminist,” she says, shrugging her shoulders. “It annoys me — that word has been villainised and so many young women are scared to attach themselves to it. I hear young women say, ‘Oh, but if I call myself that, that guy won’t like me.’ Who cares if he doesn’t like you? He doesn’t deserve you.

“I want young women to know they don’t need the attention of anyone — male or female — for their self-worth.”

Moretz attributes this solid sense of self to her close-knit upbringing in the southern US state of Georgia. The actor and her four brothers were raised by a single mum.

“Everything that people look to as rocks in their life — like a father — I didn’t have. My mother is a great support, but I realised no-one’s going to make a path that’s easier in life for me; I’m either going to sink or swim. I decided to not just swim — but to surge.”

Even so, she has been running into some powerful currents on the way upstream. Until last year, she dated Brooklyn Beckham.

The two maintained a very millennial relationship, posting loved-up Instagram photos, hitting red carpets together and cuddling on the cover of Teen Vogue. Then it all went bad.

“I went through a hard year and I’m not going to hide that,” Moretz confirms. “I had to deal with this new level of fame while I was growing up, I was getting out of a relationship and all of it was very public. I wanted to hide.”

To refuel, she says, she went into hermit mode by staying home. Again, it was her family who helped her bounce back.

“They were like, ‘That’s all great that you want to go away — but you can’t. You are your own person. You’re going to have to deal with this sort of thing.’ I felt like things were falling apart, like my head and heart weren’t in the same place.

“Things started to change when I realised I have the power within to change them.”

She brings this same attitude, perhaps now more than ever, to her work. Moretz cites Julianne Moore (her co-star in Carrie) and Meryl Streep as role models. Like them, she wants career longevity and this means taking on roles others may not view as the best option.

“I genuinely follow my gut in picking material. I never choose based on budget or money.

“It is always creativity driven and truly based on whether or not I can move on without depicting [a] character cinematically. I want it to be something that, no matter what, I’m proud of.”

Not long after she met with Stellar, Moretz all but confirmed she was back on with Beckham by liking one of his Instagram posts with a heart emoji. In the weeks following, the pair showcased themselves wearing matching outfits and dancing in a supermarket aisle.

They wore rings with each other’s initials and were caught by paparazzi shopping in Dublin, where Moretz was filming The Widow, one of her five films set for release in the coming years. The Irish skies look gloomy in those photos, just like they were during that party in New York.

But Moretz herself looks warm and happy — and it reiterates one final thing she told Stellar. “I am young; I’m still growing up. I hardly have anything figured out, but I’m trying.”