You told MIL to celebrate on the other day with you? You have every right to cut off SIL, and every right not yo go to your ILS, but you do not have the right to demand when they celebrate and that they accommodate your family on a day that it suits you. Don't send your dd there alone.
Just stay home, don't make demands of people to host your on another day. That is not ok. Celebrate at home, stay at home, and don't have MIL watch you kid.

Anonymous wrote:While I see your point about SIL I think you are elevating the drama with MIL and presumably everyone else in DHs family other than the one cousin. I don't see why MIL can't come to the recital since it doesn't involve SIL. Just make clear that you will not be discussing the topic of SIL and Christmas. If she raises it don't respond, change the subject. Don't take the bait.

THIS is the most salient point of all the responses, OP. OP is directly contributing to the family's disfunction by stepping in and stirring the pot.

Your SIL might have ASD, that comes with lack of empathy and lack of social skills that she seems
to exhibit. It is not exactly her fault. The meds also would not help with this as no meds help
in ASD as such. You might want to read about ASD in adults and see if you find this
applicable, this may help you to find a way to understand and relate to her better.
You might go to therapy and learn more about how to deal with someone with ASD.
This is not a mental illness. It is different wiring of the brain.

No, you do not ask her not to come. That would be what someone who loves drama would do. Instead you plan to focus on your kid and ignore your MIL. You smile at her if she shows. If she brings it up, simply say, “I’m not having this conversation with you. I’ll see you soon.” Smile and walk away.