don't let her openly disrespect you, if she says something rude, cruel or mean, never be afraid to call her on it, "that was disrespectful, I didn't deserve than and I expect an apology"
I don't care if she apologizes at all, you continue holding that line when she does something mean spirited or cruel. If she's been used to disrespecting you and doing it openly, you either remove yourself from the situations that allow that to happen or you call her on that crap behavior.
If she smartens up and apologizes, great, if she doesn't, her loss, just don't reward her behavior with your attention.
