How do I deal with this mother-in-law?

My husband and I have been married for 5 1/2 years. Until now, I thought it was just me thinking she was a pain so I kept my mouth shut. Now, I come to find out my brother in-law and his soon to be fiance can't stand her either. She treats my husband and his brother like they are six, pouts and over dramatically pretends to cry when she doesn't get her way and says things like "are you having fun playing house" and refers to me as a "child bride" because we got married when I was 20. She asks akward questions that she knows you can't answer thruthfully without being rude and is very manipulative. That having been said, she is not a bad person, she just wants to feel like her sons (30 and 24, respectively) as well their wives need her in order to function. She tries to downplay our independence to make herself feel more important, despite the fact that we don't exclude or ignore her. Anytime I try to talk to her about her behavior, she puts on one of her pouting shows. How do I deal?