I want Roselia to find out and deal with this on her own ヾ(❀╹◡╹)ﾉ~

What would she do? Sprinkle fairy dust and hope everything would go well?

I feel like you're underestimating her

Yeah, I am.
I've been waiting for her to realize the reality of that family. And possibly make some kind of profound impact on them.
But honestly, all I see is a happy family built on lies because she doesn't understand what struggles both the ML and the kid go through because of society. She's in her own happy bubble
Maybe this assassination attempt would move the plot faster. I really hope so.

This is exactly why I want her to find out and deal with it on her own. She needs to wake up and realize exactly what kind of family she married into and how to behave accordingly.