Sansa is incredibly hungry and she finds herself nodding in spite of her natural hesitance to trust anyone. This woman cannot possibly be from Westeros, not the way she speaks, and there's no reason to believe she's in league with Ramsay. None whatsoever.

"I would like something to eat. I don't have any coin to pay you but I will pay you back, I assure you. I won't let the debt go unsettled."