What should I do about my mother-in-law?

I had my daughter's 6 yr old family birthday party yesterday; my mother -in-law had a melt down after seeing her son (my husband who is 42) have a meltdown about my son leaving pee on the toilet after going potty. It was at the end of the party and my sister was there whom I hardly see and also my mom was still there and me and the kids too. She started ranting and almost dancing in front of my sister saying how no one in the family helps her son (which is not true we do help, but hub is very picky about things). I was so embarred that she kept moving from room to room with the rant so I got my coat on and went into the van and waited for my kids to come with me and leave. I could not tell my sister thank you for coming or goodbye. I did not say anything to this MIL and was so depressed last night that my daughters birthday party was ruined that I just went to bed at like 8:00 p.m. I called my mom after she got home and she was like, candy, we know that she's an attention monger. She felt bad for me. What should I do though about her actions? I plan on taking the ignoring option. No more answering her calls, no more of her coming over to our house to "help" us. She needs to kiss my feet as far as I'm concerned. I almost put a plastic bag over my head last night I was so depressed and suicidal from THIS.