I say this fairly frequently around here, but no one thing got you here and no one thing will make or break things. It took a long time to get to this point and will take a long time to resolve it. Don't sweat the small convos. Try to listen and validate and be polite, and if you are and she reacts negatively then you know it's because of some internal conflict and not anything you said or did.
"What is best for my kids is best for me" Amor Fati Link to quotes: https://www.divorcebusting.com/forums/ubbthreads.php?ubb=showflat&Number=2879712