On a parallel anecdote. Installing Ubuntu on my parents PC sure did reduce the amount of assistance they needed from me with crashes and malware. I'd recommend it to anyone who needs to spend some time helping non-tech friends with computer problems :)
The only problem so far is - once a year they need to use free windows-only application, that doesn't run in WINE, to calculate taxes. They just go to neighborns for a few hours.
My sister also has Kubuntu on her laptop, but she knows how to update it, so I don't know which version she runs now :)
If your relatives only use computer to browse web and write simple documents - linux requires less maintanance. At least that's my experience.