I’ve argued in previous essays that Sansa like her brother Bran is a greenseer. Some will no doubt say that this is a tin foil or a straw-man theory. To that I will say that all theories are ultimately tin foil until confirmed or proven wrong by George in the pages of the books. Be that as it may, if my theory is correct, then it makes sense for George to have dropped some clues by comparing her to Bran who we know is definitely a greenseer.