I love my Global knives, and they are unique and very clean looking. Seeing as your mom isn't a serious cook, I'd forgo an expensive set and just get a few key knives or a smaller basic set.

They have a 3-piece set with an 8" chef knife, 5" utility knife, and 3.5" paring knife which you could suppliment with a knife or two. They also have a 5 piece set which includes the above 3, plus a slicing knife and the knife block. Probably all she would need and you'd stay below $400.