Who is Grandmother Patience from Our Only May Amelia and what is their importance?

Grandmother Patience is Pappa Jackson's mother. Grandmother Patience is an unkind and cruel woman. Several years before the year in which this novel takes place, Grandmother Patience insulted Momma Jackson in her own home, causing a rift that was never resolved. However, Grandmother Patience has become old and frail. It is tradition that the eldest of the children take care of the mother in her final years; therefore, Pappa Jackson agrees to allow his mother to come live with his family despite the feud between her and his wife. This causes an upheaval in the home, especially when Grandmother Patience begins to treat May Amelia with an especially cruel type of discipline.