With her white face and black hair, her repressive religiosity and hot temper, Granny comes to represent everything that Richard must struggle to escape from. He and she are locked in warfare. It seems to be an irrational conflict at first, but soon it becomes clear that a clash of temperaments is not the only problem between them.
Hers is the first white face he knows and it is the face he dreads most. She has absorbed those qualities of white society that are intolerant, puritanical, oppressive, and fanatical. She uses the Seventh-Day Adventist faith as the weapon for all her venom, just as the white Protestants have done. She makes her church into a citadel of respectability and tyranny. She stands in the way of Richard's natural curiosity and impulses.
The word of God is the law down to the most trivial activity. Everything that is life-giving and pleasurable even food is sinful, drained of its flavor in her hands. The fact that she cannot drain Richard of his energy, hopes, and boyish spirit is frightening to her. Consequently, he is doomed in the eyes of her God.
That she is physically white effectively prepares Richard for the culturally white society around him. It is ironic that what he receives from her religion the beautiful language and the mystery of sound and meaning is the opposite of what she wants him to receive. Austere and merciless, her character is a training ground for his development in white America.