I'd start with a bolt action or single shot 22lr rifle, not a handgun. There will be much less pointing the barrel in the wrong direction if she has two hands on the gun. You mentioned laser grips. You ought to be able to find a laser you could hang on a rifle, on a 22 scope mount, or perhaps with a barrel band mount.
I am really concerned about her starting with a revolver, in any case. My experience with people with weak vision is that they crowd whatever they are holding. With any revolver she would be endangered by the barrel-cylinder gap. Plus, if she crowds the gun and has a poor grip, she will be endangered by the recoil of a centerfire.
But, you are there, and all I am doing is guessing. If she can get a good grip, keep the muzzle in a safe direction, and the gun not in a position to endanger herself, she will have a chance to enjoy the sport we all love. I wouldn't bring up hunting until she, and you, are comfotable with her target shooting. Think about plinking, and reactive targets - they give instant feedback.
You are trying to do a very worthwhile thing. Good luck, and please keep us cut in.