I was talking about collective trauma which OP was citing, though their initial term is collective PTSD.
Why would you use n-gram and not journal search engine like Google Scholar. There seems to be an engagement in the concept of collective PTSD since about 2007.
Is this an area of research or practice for you? It is not mine.
You’re using rationality to defend your behavior instead of connecting emotionally around a fundamentally emotional issue. This doesn’t mean that her behavior was justified either, but rationality will only get you so far in solving this problem. Arguably, there’s an intimate and emotional reason you’re together. If you’re both not engaging in protecting and growing that first, then you’ll end in a you vs her situation.