@BrightSideOfTheMoon if it does sound similar, then these are a few things that have helped me in my communication in relationships both with partners and my ND kids that may help.
She needs to feel that you are 100% on her side and want to work on a better understanding. As someone with ND I am really sensitive to criticism and take it as rejection. So being verbally reminded of this in a positive way really helps.
She will think that you have not taken on board and valued what she is saying. I think you have to find a way to acknowledge that, even if that wasn't your intent. It will be hard to move past without that acknowledgment. And work towards her being in a place she can see that about you, but as the parent I find I always have to be the one that apologises first for my part in misunderstanding for my kids to be able to then apologise too.
Trying to take the emotion completely out of the conversation and approaching it with a problem solving attitude has worked really well for me. It removes any blame.
Making it very clear that this is a difference in communication, not that it's her not communicating effectively. I have seen ND people describe it as being on different operating systems, so Apple and android, and I've found that really helps. If she feels that you are trying to fix her to be more NT, or that she is wrong, then I imagine she will find that really hurtful.
For my relationship, as I am diagnosed we talk about the ND almost as a 3rd person in the relationship. It removes a lot of accusations and blame about intent and has really helped.
Stepping away if it becomes heated, but still coming back once everyone has calmed down. And keeping emotional conversations short. I can manage maybe 20 mins max.
I find writing a better way to communicate than verbally. It gives me time to pause and amend what I want to say. And time to process the other persons point of view instead of reacting. And it also provides a record so everyone can see what was said.
I hope some of that helps. It sounds like a difficult time for both of you.