InStyle June 2017: Sophie Turner
Credit: Carolina Herrera silk blouse. Altuzarra silver- and gold-plated earrings. Photographed by David Schulze.

In her role as tragic heroine Sansa Stark on Game of Thrones, Sophie Turner has exquisitely suffered her way through arranged marriages, bloody murders, and double-dealing power plays over the show’s six-year run.

But ask her for clues about GoT’s eagerly anticipated seventh season, which kicks off on July 16, and the 21-year-old Brit sheds Sansa’s regal bearing. “I have to be careful because I’m such a blabbermouth,” she says, curled up on a sofa in a Hollywood photo studio. “I’m so passionate about the show, and it has been my life for so long that it’s become real to me. So whenever people ask me about it, I want to tell them everything!”

InStyle June 2017: Sophie Turner
Credit: Alexander McQueen jacquard cotton poplin dress, leather corset belt, and pyrite earring with attached cuff. Photographed by David Schulze.

Turner has little in common with her onscreen alter ego. Unlike Sansa, who wanders Westeros in embroidered silk gowns and enough gold brocade to make a Byzantine emperor blush, the actress takes a decidedly modern approach to fashion.

VIDEO: Winter Is Not Coming, Sansa Stark's Summer Beauty Tips

“My favorite designer is Nicolas Ghesquière. His aesthetics and his shapes are so amazing, and he incorporates so many different eras into his clothing,” she says of Louis Vuitton’s creative director. “But in my normal life I like to wear more tomboyish things. I like Opening Ceremony and a lot of men’s shirts and hoodies. I think it’s way cooler to be effortless.”

Likewise, when it comes to glamming up, Turner leaves the heavy lifting to her team of pros, maintaining a low-key approach when she’s away from GoT’s production headquarters in Belfast, Northern Ireland. “I’m not talented with my face. I can’t figure it out,” she admits. “I’ll put on a bit of mascara and conceal my spots. In a job where you’re constantly wearing makeup and having your hair done, it’s nice to be plain and free.”

Having grown up in front of the HBO cameras, Turner voices doubt that she would have had the fortitude to stick with acting were it not for the reassuring influence of her co-star and friend Maisie Williams, who plays Sansa’s swashbuckling younger sister, Arya Stark, and turns up as “Bae” all over Turner’s Instagram, which has 4.7 million followers.

InStyle June 2017: Sophie Turner
Credit: Stella McCartney faux-leather dress. Adam Lippes cotton top. David Yurman spinel and sterling silver earrings. Photographed by David Schulze.

“This has been amazing and hard,” says Turner, who is from Northampton. “To have someone who understands what you’re going through, who’s the same age, who came from pretty much the same background—that is so rare. And we’ve had the same struggles in terms of dealing with body image and puberty and growing up in the public eye. But I found my strength in her, and I think she found her strength in me.”

After delivering dramatic performances in a pair of little-seen indie films and a music video for the British pop-rock group Bastille, Turner took her biggest step outside the GoT fold last summer, appearing as part of an all-star ensemble cast in the hit superhero action flick X-Men: Apocalypse; she plays the auburn-haired telekinetic mutant Jean Grey. But since November, the actress’s personal life has seemingly eclipsed her professional accomplishments—one side effect of dating Joe Jonas, 27, the former Jo Bro–turned–frontman for the chart-topping dance-rock quartet DNCE.

Although Turner prefers to “keep things pretty private” about their relationship, she allows that there are concrete benefits to going out with another famous person. Not least: unspoken familiarity with the challenges of life in the spotlight. “I found it easier to date someone who understands the industry or is in that world,” she says. “You realize that you’re not going to see each other all the time. And you don’t feel like a jerk when you’re like, ‘My publicist says I can’t do this … ’ ”

InStyle June 2017: Sophie Turner
Credit: Dior wool dress and antiqued silver-finished earrings with clear crystals. Beauty Beat: Swipe on Laura Mercier Crème Smooth Lip Colour in Crème Coral, then blot with tissue for a stainlike finish. Photographed by David Schulze.

As if a fulfilled relationship weren’t un-Sansa enough, Turner differs from her character in an even more obvious way: Her natural hair color isn’t auburn.

A natural blonde who’s been masquerading as a redhead all these years out of fealty to fantasy novelist George R.R. Martin’s original description of her character, she bleached her nearly waist-length tresses to portray a troubled teen in the upcoming independent drama Huntsville. “I got to cover myself in tattoos, and I had an Alabama accent—it was such a change,” Turner says. “It killed my hair. I would never normally do it. I loved having that red hair and feel like it’s part of me now.”

It raises the question, of course: Which color has more fun? “I used to think blondes do,” she says, tilting her head back with a knowing smirk that Sansa would appreciate. “But now I think that reds have more fun.”

Photographed by David Schulze. Fashion editor: Ali Pew. Hair: Ramsell Martinez for Streeters. Makeup: Pati Dubroff for Forward Artists. Manicure: Marisa Carmichael for Streeters.

For more stories like this, pick up InStyle's May issue, on newsstands and available for digital download May 12.

InStyle June 2017: Sophie Turner
Credit: Céline silk satin dress. Ellery gold-plated earrings. Photographed by David Schulze.
InStyle June 2017: Sophie Turner
Credit: Proenza Schouler leather top. Closer by WWake sterling silver earrings. Beauty Beat: A dab of Glossier Haloscope in Quartz gives lids and cheeks a healthy glow. Photographed by David Schulze.
InStyle June 2017: Sophie Turner
Credit: Brock Collection dress. Buccellati earrings. Photographed by David Schulze.