What about a remote service like
LogMeIn? I used it with a previous client and it worked great. He was completely computer illiterate and couldn't do much of anything on the computer himself. With LogMeIn (which is free) it must be installed on the client's computer first. So, you might need to walk her through installing it unless you can actually go there and do it yourself.
There must be an internet connection available. You log in from your home and it's like you're sitting in front of her computer. You have complete and total access. She can see everything you're doing (even moving the mouse!) The only problem is that if you are logged in to her computer, she can't use it.
Just a thought.