The 21-year-old actor, who plays Sansa Stark in the show, revealed in an interview with Variety that the show got "six or seven months left" on production.
"We started in October, so we're maybe like a tenth of the way through. No, no, we've got six or seven months left," said Turner.
Turner also gave a sneak-peek into the challenges her character faces in the eight and final season.
"It's going to be tricky for her, because at the end of last season, she felt that she had everything set up... This season, there's a new threat, and all of a sudden she finds herself somewhat back in the deep end.
She also talked about her upcoming projects, including "X-Men: Dark Phoenix", in which she will reprise her role of Jean Grey.
"Yeah, I'm really excited. 'Game of Thrones' comes out in 2019. 'Dark Phoenix' is in November. Then I have a couple indie movies coming out. I'm a producer on my next movie (Girl Who Fell From The Sky). So I'm really excited about the future," Turner said.