I’ve never had a problem with how Sonarr handles anime. It works just as well as anything else.

Host it exclusively to her user or don’t host it at all. If you’re not going to host it, you know your mother better than any of us, so you’ll know which approach would work better.

It’s the person’s mother, and they already accepted the request. I feel like giving her a price quote is a huge jackass move.

As far as filtering your feed goes, RSS-Bridge is your best friend. Interacting with your feed can then be done through dedicated apps, both on mobile and desktop, if you prefer that to the native interface.

I use FreshRSS in combination with FiveFilters and RSS-Bridge to get full articles, instead of just snippets, and filter out content I already know I have no interest in.

Not exactly what you’re asking, but I can recommend Audiobookshelf.