The worst part about the maid according to the novels?
She's being actually sincere when she says she was worried...no really, it's revealed that after Penelope reveals that she always knew about the needles and never said anything, and even let her go unpunished and still working for her, she had a big realization on how much of a jerk she was and that Penelope is a much better person than she thought and decided to become genuinely loyal to her.
A bit too late, but at least it didn't take her almost dying, and no, Penelope doesn't forgive her anyways, though this causes problems as she always plans around and suspects that Emily will try to betray her or do something because she can't trust people after years of abuse, particularly someone that stabbed her with needles, when the maid has actually become genuinely loyal, regrets everything, and is willing to do anything Penelope asks her to do, even crimes, just because she really does owe Penelope a lot.