Answer:
Georgiana Irby is the mother of Mary Ann Irby, Jacqueline's mother. Hope, Odella, and Jacqueline live with her and Gunnar for a large amount of their early childhood while Mary Ann is living in New York City. Since Georgiana grew up in the early 1900s in the South, she has strong memories of the outright oppression of African Americans. Even when Jim Crow laws are abolished, she refuses to shop at stores that mistreated her or other African Americans. She is a devout Jehovah's Witness and makes Hope, Odella, and Jacqueline practice her religion as well, even when they move to New York City.
Gunnar Irby is Jacqueline's grandfather, the father of Mary Ann Irby, but the children call him "Daddy." Of all Mary Ann's children, Jacqueline is closest to Gunnar. Gunnar believes in nature and farming, and he does not share Georgiana's religious faith. When he dies, presumably of lung cancer, Jacqueline is devastated.