Hm. He takes a moment to see if that'll let her gather her wits. He can't get annoyed with her BACK, because he knows enough about her and her story that this Alessa thing is probably Really Big.

"How does Cheryl fit in?"

If Cheryl was a separate half of her, would that imply that Alessa is her ... well, 'real' half? The one that lived on? The name that was replaced with Heather's?