I’d keep the physical library around and just digitize as and when she asks for specific stuff. You’ll probably never back up half the library. That or stick it on a HDD out of the way and transfer the few she wants, then tuck the drive in a draw forever in case she wants something else.

Jellyfin must have a feature like Plex where certain user accounts can have certain libraries attached? You could use that to avoid having to look at those crappy movies in your library.

I don’t really have much of an issue with family recommendations but I do tell them that the space isn’t unlimited so if they don’t watch something they asked for I’m likely to remove it for something we WILL watch. In your case, you could at least have leverage to get her to narrow down what needs hosting and what doesnt.