"Hey," stepping a little closer to try to get him to look at her again. "I like you. And you can't help this situation any more than he can. You aren't doing anything wrong, and- and I like seeing you."

Which is why she feels guilty. She doesn't know what Gerard is exactly, if Iris is right and he's a piece of Sweeney that needs to be integrated somehow. She does know that it hurts Sweeney and she does not want that; but she also doesn't want Gerard to hurt.