Vicious mother in law..

Story

My boyfriend and I stayed with his family 3 hours away from our home for family christmas with that side of the family. Well, NYE we weren't drinking because we were staying with his grandmother that does not approve of alcoholic beverages. My bf and his siblings started arguing over something silly, when my bf's mom jumped into it and basically told them to shut up. then, she brings up how often that he and I bicker and that she is sick and tired of me and tired of me constantly belittling him, even though we really do not fight.... anyways, I go into our room and get our bed ready and go to take my daughter from my MIL, when she THROWS my daughter's blanket onto my shoulder. I replied with "seriously? What did I do to you?" And then she starts AGAIN with running her mouth about how much she can't stand me & how she is miserable being married to my bf's father for 20 years! She keeps running her mouth, so I try to ignore her and walk to the other side of the kitchen to get my daughter ready for bed when the MIL gets in my face and starts yelling. I start clapping and tell her to BACK UP when she body slams me onto the ground (no exaggerating) and whoops my ass & I don't fight back because I respect her... for some reason. It's been 3 days, we are not speaking, but she has contacted my bf and would like us all to sit down and "talk". What should I do? And she broke my glasses, I'll add. Pictures are of my neck/face.