I agree that it sounds like she was joking, but there is a very fine line when joking on an airplane. They can joke with us, but we take risks joking with them, because they have power over us, and we never know how they are going to take a comment made in jest. Or, for that matter, how they would react if we misinterpreted one of their joking comments.

Keep the mutual respect high, keep the jokes light and obvious, and it's all good.