Where does she sit in the hierarchy in relation to you? Are you at the same level?

Sometimes when I feel like people are trying to drive me crazy on purpose, I try to imagine other explanations for their behavior. Like with your coworker, I might think 'oh, maybe she is so stressed that she has no idea what she sounds like. She probably felt bad about what she'd said before she left, so she insisted on doing the chocolate ganache.' That interpretation may not right, but it's possible, and it's easier to deal with someone (for me), if I can attribute their annoying behavior to an oversight as opposed to a personal slight.