After the "Battle of the Bastards", Game of Thrones fans began to hail Sansa Queen of the North and with good reason. The only reason Jon Snow was able to defeat Ramsay Bolton was because Sansa sent a letter to Littlefinger and he, along with the Knights of the Vale, came to the rescue. If it hadn't been for Sansa, Jon Snow would've lost and most likely died and one only knows what could've happened to Sansa. It's clear that Sansa knows what it takes to be a good leader, and that's just one of the many clues that Sansa will probably rule Winterfell.
Sansa has been through a lot. From the time she left Westeros, she had to watch her father be beheaded in King's Landing, stay there and play nice with her enemies, get married off to Tyrion and then later Ramsay, where she was raped and abused by him. The list goes on and on. But through all those terrible experiences, Sansa has learned a lot and now, although she still holds a lot of the qualities of a Stark, she's also more ruthless and empowered. Sansa's ready to do whatever it takes to get what she wants and to make sure no one has power over her ever again. There's no doubt that she's ready to rule Winterfell.