Hey FIB, checking in with you. I have to agree that the texts are not getting you anywhere except going in circles. She is going to tell how she remembers things and there is nothing you could do about it.
I dont know what you should do, but, I think that something has to be done. There has to be something put in writing. However, there will be times, like this past weekend, when things come up so you both have to try to put the children first.
I could only imagine how difficult this situation is for you. FIB, this is someone you have to deal with for many years to come. It behooves you to try and figure out a way to deal with her. I hope once you are not living together that things become more tolerable.
As always, my offer to speak with her stands - LOL!