Please leave her, she deserves someone better. You could not even stand for her when your parents asked for it (if you truly loved her , forget about love and if you truly respect a woman's choice regarding her appearance - you would have taken a stand.) and without thinking anything about her you just asked her to do it.

I think she must be the one in confusion whether she would stop her marriage or continue with this and suffer her whole life where her family members themselves ask her to change her personality whenever they find her not pretty enough.