According to Isaac Hempstead-Wright, who plays Bran Stark in the show, Sansa’s storyline was not as manipulative as all that – she really did fall under Littlefinger’s thrall and came dangerously close to killing Arya. We just couldn’t tell because the scene explaining all that was cut from the finale.
“We actually did a scene that clearly got cut, a short scene with Sansa where she knocks on Bran’s door and says, ‘I need your help,’ or something along those lines,” Hempstead-Wright told Variety. “So basically, as far as I know, the story was that it suddenly occurred to Sansa that she had a huge CCTV department at her discretion and it might be a good idea to check with him first before she guts her own sister. So she goes to Bran, and Bran tells her everything she needs to know, and she’s like, ‘Oh, s—.’”