My Mother (now in her late 80's) has been using Linux and KDE since I gave her a computer back in the 90's. I had it dual boot for a while but finally gave that up when I spent far to much time fighting windows. By then she was comfortable with Linux and only needed one windows program that I was able to run under Wine.
Other family members have accounts on the same machine so they have net access when visiting ( less of an issue now with tablets and laptops) and I handle the admin details. I'll be visiting her this weekend and will probably spend less than an hour updating and checking logs. My last visit to do this was Christmas.
It's a no-brainer.