Why do people consider Sansa keeping things to herself as having backbone? She was wrong for not telling him plain and simple. They were almost slaughtered. She went to Jon for protection and then severely limited his ability to win by not telling him about all of the potential soldiers she could bring to the fight. Yes, it wasn't a guarantee, but I think that most of us knew LF was dying to make things up to her.
As others have mentioned, the issue isn't whether she could guarantee he would come anyway. It's about not telling Jon at all. How many times did she tell him they needed more men? How many times did he tell her there weren't anymore? He may have waited if there was even a slight chance they could add that many people to their numbers.
As others have mentioned, the issue isn't whether she could guarantee he would come anyway. It's about not telling Jon at all. How many times did she tell him they needed more men? How many times did he tell her there weren't anymore? He may have waited if there was even a slight chance they could add that many people to their numbers.