For her father to be so concerned with the family's honor, he's been woefully neglecting every single action needed to at least keep of the facade of Penelope as the daughter of a noble family. Thankfully she trapped him with that, and it'll likely be a useful card for actions she takes to protect herself in the future.
And I think her "family" is only now taking an interest in her because she's proving to be something other than a childish, tantrum-throwing placeholder - she's actually showing how she can be useful, and thus "human" in their eyes. Which makes them terrible fething people and i hope she keeps that in mind as she plans her escape.