Puffytail,
You can have your mom drink coconut water also; it is very good for electrolytes and it's natural so it does'nt have the sugar like gatorade or powerade. You can get it at Wegman's in the Health Food section or at a Health Food Store; it comes in a container like a juice box. I have found the ZICO brand to taste the best.
I wish your Mom the best,
Judy