For MMGM, I am recommending Hour of the Bees by Lindsay Eagar.
(This cover is the redesigned version for the paperback.)
Here's the publisher's description:
While her friends are spending their summers having pool parties and sleepovers, twelve-year-old Carolina — Carol — is spending hers in the New Mexico desert, helping her parents move her grandfather into a home for people with dementia. At first, Carol avoids prickly Grandpa Serge. But as the summer wears on, Carol finds herself drawn to him, fascinated by the crazy stories he tells her about a healing tree, a green-glass lake, and the bees that will bring back the rain and end a hundred years of drought. As the line between magic and reality starts to blur, Carol must decide for herself what is possible — and what it means to be true to her roots.
I really enjoyed this book. One of my favorite things about it is the amount of major topics that it discusses. Carol's family is Hispanic, and her grandfather, who suffers from dementia, tries to convince her to be proud of her heritage and ethnicity. This ties in to Grandpa Serge's home, since Carol's family is moving Serge, who suffers from dementia, out of his long-time home and into a nursing facility. One major point of the book is Carol's deciphering of her grandfather's stories as she determines whether they are real or figments of his dementia. The author describes Serge's home and its desert location extremely well, combining majesty and torture (i.e. the heat). The book, narrated by Carol, is an enjoyable read, and it is not particularly depressing, despite discussing things that are exactly that. The book's small cast of characters allows each one to shine. Finally, the ending is amazing, being extremely unexpected and both sad and enjoyable. Hour of the Bees is a unique book that will be enjoyed by nearly everyone!