you hope that a stern talking to by mom or dad would do the trick, but in reality the W would see it as a violation of trust, would try to convince her parents she is right, etc. Not good. I realize that.
Also, how strong do you think that makes you look...bringing in mommy or daddy to help you. If that was your child (just saying) would you bring in gramma or grandpa to help with their behavior??? getting advice from them is one thing but having them come in and speak with your child...UUGH...