So, here is what I wrote to a friend who was interested in the accuracy of the portrayal of Cystic Fibrosis. So, if you are interested in that apect - here ya go! I have a daughter with CF and am pretty actively involved in the CF community:
As for the CF stuff, it is definitely accurate, but it is quite rare today for a child of that age to have such advanced stage disease. Not that it never happens, but rare. Most cases that are considered severe would have children who still live pretty regular lives but are hospitalized every couple months for IV antibiotics and such (a "tune up"). Also, while there is some use in moving somewhere with salt water in the air, anyone with that severe of an illness would definitely want to be near a major cf center. Salt water is probably no help at that point, and why move to the middle of nowhere instead of to like, say, near the ocean in a major city with great health care! But....all that said, those are sort of nitpicky details probably and coming from a reader with too much knowledge. I am a little concerned, though, with the outdated portrayal of CF as a death sentence in youth. It is a serious illness, generally considered chronic, not fatal, for young people today.
So, that's my critical review. Also, I really love the book. The layers and symbolism, the handling of complicated issues, the rediscovery of personal heritage ...all make this stand out. I am, though, reserving some judgement until I hear more from people of the culture she is writing about, since I am not an expert and can't judge if there is inaccuracy or offensiveness in her portrayal of Day of the Dead etc.