Honestly, it doesn't sound like you want to be around her either, remember to breathe, breathe, breathe.
And remember you do not have to respond to her email.
Personally, I do not believe this warrants a response. If she chooses to exclude you, sad as it is, so be it.
I would start making a plan for my children and myself to have a delightful holiday weekend, far and away from her insensitivity, and all the bullsh*t and drama that some people seem to thrive on, especially around the holidays.
You can get through this, perhaps it's time to start some new holiday traditions for you and your kids. ((((hugs)))