Diane Duane
Not everything can be fixed with magic--young wizards Kit and Nita are having such a tough time coping with adolescence, they go their separate ways. But then Nita gets some bad news: Her mother has cancer, and it may be incurable--by medical or magical means. 
Fantasy,Young Adult,Fiction,Fantasy,Magic,Fantasy,Urban Fantasy,Science Fiction,Science Fiction Fantasy,Adventure,Childrens,Young Adult,Young Adult Fantasy
The Wizard's Dilemma