The Commandments apply to all people. Do you really think God would be selective???
Respecting one's parents doesn't mean hanging out with them, agreeing with them, liking them or doing everything they say. Respecting means being mature enough to be polite, tactful, non-vengeful, etc.
Any woman who doesn't like her mother-in-law should simply be polite, choose not to be around her very much and YES tolerate a family member who acts stupid, crazy, etc. It's called being an ADULT. I would pity the mother-in-law, not try to instigate things and not have confrontations. That would also show respect to my spouse (whom I supposedly loved) and to myself.
Besides, we should all respect OURSELVES enough not to get down in the mud with others who are behaving badly! It's not easy to do, but it's what GOD wants us to do and we should all aspire to be better, nicer human beings.
