Okay...lemme just say before I continue "I am NOT a complete WITCH with a B!"
But I am a huge believer that you need to stand up for yourself, especially in the case of a MIL (and marriage). I believe that speaking your mind will make people respect you and will be less likely to "assume" they can say things to you that are rude or hurtful. As long as you are respectful about the way you say it, you absolutely can ream her out AND possibly improve the relationship.
I have personal experience with this situation because my MIL is very overbearing and can be downright psycho at times. DH and I got married right around the same time DH's only brother and his wife got married. So we were sorta "on par" with one another. As you might be able to tell, I am not a people-pleaser and have no issue speaking my mind. The brother's wife is an a$$kisser! She has been up my MIL's butt about everything, right in her corner since day one. Just the "perfect daughter-in-law." Me, I had it out with MIL over her pettiness, her demanding nature, and the fact that she tries to control her sons with guilt. Me and MIL get along FAMOUSLY now. She asks my opinion, is polite, and respects our space. She can not stand the brother's wife, as she can never get a true statement out of her, she is so into sucking up. She actually told me that the girl is "getting on her nerves."
Goes to show that it might do a little good to let your feelings be known, with the blessing of your DH of course! But if it is something that is somewhat "big" or that might come up again, you can totally have it out with her and let her know how you stand. And if that is not normal behavior for you...blame it on the hormones
Oh, I wanna know details too