Sometimes the correct answer to a question is one the asker doesn't want to hear.
This is the correct answer. Guy should give his mom a tablet for Christmas, for "when you'd rather sit on the sofa than at the computer desk". Six months later, either he'll find it's never used (which means he's just out some money) or that she uses it exclusively (which means the problem is solved, as she's now adapted to another OS - acceptable because it's "on a tablet" instead of another PC OS).
Tablets are what parents should have been getting in 2000-2005 instead of all the PCs that were used instead, if only they had existed in non-suck forms.