That friend uses Kodi (and a NAS) now, but it's still a bit arduous to use for his family. She wants profiles, availability on any device over wifi and 4G and movies and series only.
Don't get me wrong I have Netflix and prime but Disney plus, hulu and hbo max are not available to me so I need to work around the stupid global restrictions.
As it stands today you can build your own version of this but if you want to stay 100% above board you get a crappier experience (don't get me started on the cluster-f around rights). It reminds me of the jokes back when DVDs were still a "thing" and you had to sit through ads and piracy warnings if you bought it legitimately but if you "stole" it you were able to jump right into the movie.
The best thing about Jellyfin is that it is free software: open source, permissive license, and no paid features (which alternatives like Plex have).
You can host Jellyfin on your own VPS, I host mine on a Hetzner VPS for just over 10 eur / month but that is very overkill, you can host one for far less. The only thing to keep in mind is that transcoding (streaming in a different resolution to the stored media) is quite computationally expensive so if lot's of people are transcoding at once you will need a good CPU.
Then any family member can just visit the IP address of the server in their web browser (or you can buy it a domain name). Jellyfin has a native iOS app they can use from their phones. For viewing it on TVs, there is an app for AppleTV which has Jellyfin support (cant remember the name right now but I can find it if you need it).