If your mother is using the original iMac keyboard, have her turn the keyboard over & give it a good wack on the back a few times.
If the above does not work, then tell her to take a vacuum hose, put the furnature brush part over it & run it over the keys. Hopefully, that should do the trick.
The keys can be popped off w/a paper clip to get to the dirt & grime. However, personally I find that too inconvient & besides, my keyboard never got that filthy.
Crumbs & dust will gather inside the keyboard causing problems. Especially if you make it a habit of eating & drinking while sitting at the computer.
Good luck!
