While speaking with ET's Leanne Aguilera at the HBO series' season eight premiere in New York City on Wednesday, Turner revealed that her onscreen sister, Maisie Williams, will be her maid of honor.
It's been known since January 2018 that Williams' close relationship with Turner earned her a spot as one of her bridesmaids, but Turner couldn't help but set the record straight on her wedding day duties when she found out Williams told ET she was deciding what to wear to her wedding.
"I don't know why she's thinking about [what she's wearing to my wedding]. I'm giving her the bridesmaid dress!" she said with a laugh. "She's my maid of honor! One of two."
Turner and Williams basically grew up together on the set of Game of Thrones, earning their roles as Sansa and Arya Stark, respectively, 10 years ago.
"I'm devastated and excited," Turner said of her feelings about seeing the legendary series come to a close. "I put on waterproof mascara tonight because I knew it was going to be a laugh cry. I'm ready for it."
The actress also had another useful accessory for the tears: her fiance. "It means so much to have him here, it's just like, the best support, the best person to calm me down and keep me calm, and if I end up crying, I have a shoulder to cry on," she revealed. "So, it's good. I'm so happy that he's here."
Turner shared during an interview with ET last week that Jonas was on set during the final season of GoT so much that he ended up signing a non-disclosure agreement to learn the ending.
As for how she's feeling about what's next, she admitted on Wednesday that she has mixed emotions. "I'm petrified, it's a lot for me, but I'm excited. I'm excited for the world to see the next chapter of my life, post-Game of Thrones and I feel like a new woman."
Game of Thrones returns April 14 on HBO. See more in the video below.