There has been little research into the genealogy of either Raff's family or that of his wife, Doris Genast. The prime sources for both families are the two books written by the couple's daughter Helene Raff. All that is known about the Raff family comes from her biography of him: Joachim Raff, ein Lebensbild. Her own autobiography, Blätter vom Lebensbaum, has more detail about the Genast family. Internet research has added a few minor details. Helene Raff herself did not marry and had no children.
Genast family tree:
Raff family tree: