Jellyfin is getting closer to the same feature set as Plex, while Plex is going through enshittification, so it absolutely makes sense. I'm migrating a few people right now. The only downside is securing the service when you have non-tech family members using it. Tailscale (or something like it) is easy for folks like us, but trying to explain it to my mom... >.<
Discussion
Setup a tailscale node at their location & reverse proxy whatever services you need locally to your mom's LAN 😉