>You could zap the whole machine and install windows 10 on it maybe? I bought a el-cheapo windows Samsung tablet off craigslist a while back - so might want to see what's on craigslist.
>I would also suggest she use google chrome as a browser and install these extensions:
>adblock
>adblock plus
>adguard adblocker
>ghostery
>hide my adblocker
>https anywhere
>privacy badger
>
>..and then install a piece of software called ad-muncher.
>
>.....now folks are going to say this is overkill - but this is what I do on my machines and how I setup all my no-so-computer-savy friends machines. It doesn't take too long to setup all of these (you want all of them to NOT accept any ads, and to use all the built-in ad-blocks lists they can.) The result is that you won't see any ads at all, many dangerous websites are blocked, and thus keeps your not-so-computer-savy friends from clicking on harmful stuff. I had a neighbor that couldn't keep his computer from getting infected with something within 2 or 3 days - did all this for him and no problems since.

...or...he could buy her an iPad mini :)