Geraldine is the mother of Junior, one of Pecola Breedlove's classmates. Junior is a cruel boy who lures Pecola to his home under the guise of friendship, kills his mother's beloved cat, and then, when Geraldine returns home, blames Pecola for murdering the pet. Junior kills the cat out of resentment for his mother demonstrating greater affection towards the animal than towards him. Geraldine's inability to demonstrate love to her son parallels with Pecola's own inability to obtain affection from her mother, Pauline. While Junior should be a sympathetic figure and does truly want company, which is why he tries to stop Pecola from leaving his house, he has also been taught to position himself as superior to Pecola due to his higher class status and lighter skin color.
Geraldine, as Morrison narrates, was one of many young Black women who migrated to the North from the Deep South during the second wave of the Great Migration after the First World War. Geraldine prides herself on being a good Christian wife--that is, one who dutifully has sex with her husband but never exhibits any fondness for the act. She is particular about cleanliness and good presentation, priding herself on her home. Junior uses the comforts within the house to tempt Pecola into keeping him company.
Geraldine is also a lighter-skinned Black woman and, like everyone else in the novel, has negative associations with Pecola's very dark skin. She sees Pecola, with her uneven socks and nappy hair, and feels a disgust for an aspect of Blackness that Geraldine has worked hard to refute by establishing herself as "decent." She expels Pecola—the epitome, for Geraldine, of slovenliness and all things lower-class—by calling her a "Black bitch."
Geraldine is also likely outraged that Pecola was in the house alone with Junior, suggesting the possibility of sexual impropriety. She is the type of woman who would have been more likely to have blamed Pecola for trying to corrupt her son. This also plays into the stereotype that darker-skinned Black girls and women were more likely to be "loose" sexually.
Geraldine curses at Pecola through the fur of her dead cat and never looks at the girl, whom she deems unworthy of her gaze. Geraldine's loftier status within the Black community depends, she thinks, on rejecting Pecola. Morrison illustrates how Geraldine, like so many others in the novel, forces Pecola to bear the weight of her self-hatred so that she can eke out a more comfortable space for herself within a racist society.