By Lynette Rice
April 27, 2015 12:00 PM

Talk about growing up fast: Sophie Turner had no idea what to expect when she landed the role of put-upon Sansa Stark in HBO’s violent, racy and highly addictive Game of Thrones. She was only 13, had never read the George R.R. Martin books that inspired the series, and it was her first professional gig. “Everyone was reading lines,” says Turner. “Then it would get to a sex scene, and I was like, ‘Now I know what kind of show this is!’ ”

Turner, 19, the youngest daughter of a retired business-consultant father and former teacher mother, got her show business start as a kid, doing local theater in her hometown of Warwick, England. Early exposure to Thrones’ gory universe made Turner feel like “the most mature person in the world. I thought, ‘I can’t be doing anything like Disney right now. I have to go and be an adult!’ ” Her character has had to wise up quickly too. Once naive, Stark has witnessed her father’s execution, outlived a royal husband as sadistic as Caligula (he was poisoned) and survived a murder attempt by her own aunt.

This season the young widow may be forced to wed another degenerate denizen of feudal Westeros – if her protector-tormentor, the lascivious Littlefinger (Aiden Gillen) doesn’t get his hooks into her first. “Sansa goes through a lot of hardships,” says Turner during a visit to the more congenial kingdom of Beverly Hills. “She can’t seem to catch a break!”

In Hollywood the opposite is true. The 5’9″ blonde (she dyes her hair auburn for GOT) is a rising talent with a host of hot upcoming roles: Later this year she’ll star in the indie comedy Barely Lethal, opposite Jessica Alba, and in Alone, with Ray Liotta; then she’ll go on to play the author of Frankenstein in Mary Shelley’s Monster and superheroine Jean Grey in X-Men Apocalypse. She nabbed that last part in a decidedly modern way. “I started getting a ton of tweets saying they were recasting Jean Grey as an 18-year-old,” says the Twitter-obsessed Turner. “So I e-mailed my agent.”

Offscreen she’s settling into a new home in London not far from her best pal, Maisie Williams, who plays her little sister Arya on GOT. They hit the night scene while trying not to do “stupid things.” “Sophie’s grounded,” says Gillen. “But it’s all quite dazzling, what she’s up to.”