She's not smiling, really. It's totally a grimace and she's sticking to that story thank you very much. Because Angel being fatherly doesn't require as much of a stretch for Faith as it might for others, she can definitely reconcile his words with the actions he's displaying.

"Yours." Her eyebrows do lift, because she's going to go ahead and give you lots of room to say more words that make this all less horrifically awkward.