Originally Posted by ElizabethN
For something completely different, can she teach herself to knit or crochet? Once she can do a basic stockinette stitch, knitting can actually be really good math activity - figuring out designs requires a good intuitive grasp of arithmetic. You can encourage her to learn to alter patterns to fit. And it can be soothing to have something to do with your hands. I knitted through years of classes at MIT.
She could crochet a hyperbolic plane (google it).