This may be a rant but, why does it seem that mother in laws HAVE to be manipulative?

I thought she was going to be different than what everyone seems to say about their mother in laws, but she's not! She drives me insane and she seems to do it on purpose!This may be a rant but, why does it seem that mother in laws HAVE to be manipulative?
Confront her. I did with my mother-in-law and we've gotten on ever since. Be polite but get it across that you're not going to take any B.S.This may be a rant but, why does it seem that mother in laws HAVE to be manipulative?
Tell her son what is going on and have him deal with it.