I would pair a Synology NAS with at least one, preferably two, usb disks to make local backups to with the built in Hyper Backup - losing the whole family picture archive hurts and usb disks are cheap. It doesn’t seem possible to make a read only QuickConnect connection so beware of that if there’s to be non techie users connecting.
Personally I use dyndns and openvpn (if I rebuilt today I would look at Wireguard instead of openvpn as a vpn solution) as I prefer not relaying my traffic through services outside my self hosting. That would require you to aid your non techie family members with the initial configuration on their end though.