Hi Mahiya,
Here is my idea:
Tell your baji to realize that its HER husband, HER marriage, HER home, HER daughter, HER kitchen, HER food and HER life that her MIL is trying to steal. Then, tell her to not to get mad...get even. This is how:....
Don't get mad, get even. I LOVE IT!!!! SUPERB PLAN!!! Best response, mahiya, let us know what happens when this plan is followed.