From your description of your mother, I would also recommend Global. They are a good knife, and although most of my own knives are other brands, I almost always give Globals for wedding presents, etc. because they are lightweight yet more durable than most other knives. In the kitchen of someone who does not do regular knife care, they will stay sharper longer than a Wüsthof, etc.

Also, Global sells a line of "Minosharp" sharpeners that are basically mini-whetstone wheels set into a housing at the proper angle. Throw in one of these and your mother can do periodic sharpening herself very easily, even with no knowledge of proper sharpening techniques.
example sharpener 1
example sharpener 2