[She doesn't say anything in reply at first; instead Pepper stares at Billy as each part of what he says sinks in. His mother's there, but not the age she should be, or even from the right place. Instead she's from a time before Billy's birth, and a universe where he may never even exist.]

Oh...oh god! [Then it clicks, and Pepper again looks to the artwork with new understanding.] And you don't want her to see something that could have her asking about her future--or the future of her alternate self.