That was nice of you to set up a FreeBSD box for your Mom. There isn't a lot of work maintaining one IMO, stuff you could probably get by doing on a weekly basis for her as far as updates, and if she just uses it to surf the net, checks her email, etc. she'll be doing it in style.
Since she used DOS back in her days where she started working making digital docs for her work ( she even remembers a little of Lotus123 ), she isn't afraid of terminal and when she used ubuntu she kept complaining how the ubuntu updater was garbage so I taught her to use the "apt update" and "apt upgrade". So in the end I just said "you update this system like ubuntu but switching "apt" for "pkg"", in the end she updates her system.
She only use cloud storage nowadays, so I didn't even need to setup automount for USB xD
The other day she was on the phone with a friend and her friend was complaining about constant virus on their family computer and she just answer with that: "Oh! I don't know what is that, for like, 7~8 years now, cause I use FreeBSD or some Linux distribution + firewall" (my old family PC, now just my mother's PC still use Linux, but again with Mate DE)
I was so proud that day. :3