This game is as good as finished, so there will be no major changes like overhauling a character or scratching them altogether. Neither would it really be doable with this story, every character plays a role and the story wouldn't make sense anymore if anyone just got deleted from the game, especially the core family.
That being said, I'm just dumbfounded that someone can dislike Catherine this intensely. The raping Brenna part I guess is at least debatable. Then again, it's Catherine. My memory of the details is pretty foggy, but in the end they all made up about it. Cath does some stupid stuff at times, but in-universe they have to keep in mind that all she does comes from good intentions, and for us viewers she serves as comedic relief.
I'd have to replay the 'rape' portion of the story for the details, don't have the time now. But the fact that it didn't leave me with a lasting bad impression of her shows me it can't have been that bad.