It's the fact that she thought it was ok to lob a threat at HD's child. That is insufferable and should be stopped immediately. Surely you see the wisdom in coming down hard on that.
Mrs. Nop is right. She resents the *hell* out of his children from his first marriage...and uses not doing for them as a tool to get back at him. Big, big mistake...personally, that in itself would make me lose so much respect for her it would be hard for me to overcome it. Mostly because it has happened over and over again.