Every so often a writer invents a story whose simplicity cannot disguise for more than a few moments a work of radiant beauty and sustained power. Mrs. Hornstien is such a book. With a raw lyricism all her own, Fredrica Wagman writes of family, of passing generations, of love and striving, of grief and loss and renewal. Her narrator, Marty, begins with a day burned in her memory, when, as a young woman in love, she meets her future mother-in-law,...