Esperanza Renace by Pam Muñoz Ryan.
She uses the experiences of her own Mexican grandmother as the basis for this compelling story of immigration and assimilation, not only to a new country but also into a different social class. Esperanza's expectation that her 13th birthday will be celebrated with all the material pleasures and folk elements of her previous years is shattered when her father is murdered by bandits. His powerful stepbrothers then hold her mother as a social and economic hostage, wanting to force her remarriage to one of them, and go so far as to burn down the family home. Esperanza's mother then decides to join the cook and gardener and their son as they move to the United States and work in California's agricultural industry. They embark on a new way of life, away from the uncles, and Esperanza unwillingly enters a world where she is no longer a princess but a worker. Set against the multiethnic, labor-organizing era of the Depression, the story of Esperanza remaking herself is satisfyingly complete, including dire illness and a difficult romance. Except for the evil uncles, all of the characters are rounded, their motives genuine, with class issues honestly portrayed. Paperback, 272 pages.