Peggy's watchful of everything, making sure that if she can somehow alleviate Stella's pain or make this easier that she's able to. She's not intending to take her eyes off of Stella while she explains any of this and is cautious that she's cataloging precisely the symptoms that Stella seems to be experiencing.

When Stella tells her about the amnesia, Peggy feels a touch surprised at how vehement her reaction is. She doesn't believe it, utterly doesn't, and she's angry that this could somehow actually be a case that he could somehow be won by this. "You can't be serious," she says, giving Stella a look of disbelief, though she knows she doesn't have to convince the other woman.

"Isn't there some way of testing that, to prove that he's lying?" Because to her, there's no other possibility.