Stress is the obvious answer. You won’t be able to guess what is causing it, so don’t start speculating. You can try to impress upon her that you are a safe outlet for that stress if you are able and willing to really be that for her, (Don’t just jump at it because you are curious. You might not like what comes from it, and it’s worse to pull back after the fact than to not offer at all.) or you can just be a source of stability while she works through it herself. Use your best judgement.
Do you have a definition of fascist you approve of, or would argue for? It’s absolutely true that some people throw around words as dismissal but that doesn’t mean we just all throw up our hands and say all words are meaningless.
Ultimately, the fight over ‘fascism’ is a fight to define ‘fascism.’ Having no definition is not a position to argue from. It’s ignorance. Arguing on behalf of ignorance is just noise. Even if no one else shares your definition, decide what it is, then argue for that.