Joe, I think your best course is to start working with her, fixing things that need it around her house. Because there are just so many different ways to fix things.

I once fixed my dishwasher by using the military's first solution - RTFM. But I had to give up on my breadmachine. All it needed was a gasket, but the replacement gasket cost almost as much as a new unit. And I might not install it right.

So to answer your question - how do I teach her to fix things? I say this:

1. teach safety
2. teach her to use the owner's manual, which usually has a section on troubleshooting
3. use YouTube
4. then go case by case