I do have hand handicaps.
I use an Alto's QuiltCut2 for my cutting as it takes only 1 pressure point to keep it in place and is accurate. Yes, I use whichever hand hurts the least when cutting.
I use a 1/4 foot with a flange guide or an seam guide when sewing my seams.
I have the little 'birdie' type Third hand also. Nancy's Notions carries it as do other sources.
I also have another Third Hand from a Mr Quilt, though I don't think he is in business anymore. It is like a square Brooklyn revolver with a C type clamp positioned over the center of the revolving portion that I can screw down to hold my acryllic templates in place while rotating the fabric so it is easy to cut all sides of the template.
I have played around to find which ruler stabilizers I like: the sandpaper dots are second to the acryllic dots.
There are lots of aids out there. Keep looking and trying ... if that is what she wants to do, she can do it.
ali