Peggy's not so sure who the 'him' in this question is. Even if she were feeling fully herself, she suspects that she would be a touch puzzled and it likely shows in the way she frowns, watching him warily.

"Who?" she asks, because it's best to simply get bluntly to the point rather than dance around it too long. "Who did you forgive?" And what was there that needed to be forgiven in the first place?