You know this is all so familiar, amazing I have had to deal with a crazy mother of a classmate of my daughters all year too. My daughter has a love/hate relationship with a classmate and I got too involved and the other mom pissed me off big time.
She went to the principal because she heard my daughter was being mean to hers. The counselor pulled them into his office and talked to them both, both are guilty, however the mom told her daughter she could not play with mine anymore. So of course mine ran home in tears! I think that is so wrong. This issue is just ridiculous to be honest and I think at this point us parents need to let the girls work it out alone.
Due to the issues coming into the classroom they had to stay on seperate sides of the playgrounds alternating every week for three weeks! It was so stupid! They are in second grade. It did help to a degree and my daughter just adores this other girl. There was another girl involved which always adds chaos as three can be tough as someone is always in the middle. I tried explaing, lecturing you name it.
She seems to think her daughter is flawless and I have heard the way these girls hurt each other with words, MY DAUGHTER is no saint and I hold her accountable completely. But I have also seen her daughter in sass action and it isn't pretty.
However, that all said, you cannot fight the battles for your child. I am learning as I go. You just need to teach her to use her words carefully, to realize nobody can take her friends away and that she needs to walk away if the situation gets hairy.
Yesterday I made a blanket statement to my daughter "you choose who you are around, if you choose to be around someone that is mean and nasty then you are going to get your feelings hurt, then it is on YOU, not them". "True friends will be there for you and not purposely try and hurt you, be with people that make you feel good about you". I explained she knows it is a matter of time before feelings are hurt. She wants to be friends with this girl so badly and I have no idea why. When they get along it is beautiful, however it is back and forth constantly, but not my problem to solve anymore.
I explained being mean with words to hurt someone is VERBAL bullying, it is no more acceptable then regular bullying. You can only reassure your daughter that nobody can control another person, so her friendships are something that this little girl cannot disrupt, it is freedom of choice. Ultimately I always remind my daughter that if someone talks behind someone else's back it will end up biting them in the rear end and to ignore it.
Just yesterday she said that the girl said she didn't like her and made a mean face at her...., WELL HELLO!! STAY AWAY THEN! Of course that falls on deaf ears so I just ignore it really at this point.
I have tried to just bite my tongue. The other moms continues to interfere to the point of telling her daughter to tell me that she isn't fond of me! Who does that? I don't even really know this woman. My daughter relayed the information and asked if it hurt my feelings, I responded with "you know it doesn't bother me at all, we all have a right to our opinions and she doesn't know me, so I cannot take it personally". I would try and set up playdates outside of school thinking that would help, the woman was bold faced rude about it, saying her daughter is timid and it isn't a good situation, her daughter is two feet taller then mine and both girls are fickle and can lash out!! Neither is guilt free.
You say you "think" this is due to the falling out with the other mom, if so then you should address it with her but be certain that it isn't just basic peer issues going on. If you know it is pointless then I just suggest you maybe realize school is almost out, they have all summer to be apart and kids grow and change so much over the months. You taking the high road will set a great example for your child.
I can personally say I don't advise going to the principal and pick who is what class next year, that makes you involved more then you should be. I see that as overstepping in my opinion. They will still see each other at recess and lunch times and what are you really sending as a message?
They can play together or not, if they do then your daughter has made her own bed if she ends up in tears.
I told my daughter I will be sympathetic until you choose not to take control of the situation and walk off before it esculates, if you choose to put yourself in the line of fire then I have a hard time feeling badly any more about it. Sounds harsh but NOT everyone is going to like everyone, it is about self esteem which needs to be worked on at home and hoping they carry themselves in a manner at school that doesn't allow them to be hurt. Being hurt it is bound to happen even if you have no issue with the other parent.
Sorry for the blather of the long post....I just know how you feel, however I think it is a fine line when parents need to be involved. I think it is best to let the school year wrap up and move forward.