What are the differences between Squeaky and Raymond in "Raymond's Run"?

Squeaky is Raymond’s younger sister in “Raymond’s Run” by Toni Cade Bambara. The two characters have many differences in the story.
Raymond is Squeaky’s older brother. He lives with a developmental disability. He needs constant care and direction to ensure his safety in their Harlem neighborhood. Occasionally, he creates a stir with his escapades of running through pigeons and upsetting people in his wake. Other times, Squeaky has to corral him away from the curb for his own safety.
Squeaky is a spunky, spirited young girl with a fiery personality. She takes her role as Raymond’s caregiver seriously, but rarely sees him as a person with potential. She is dedicated to her running, unafraid to fight when defending her brother, and has an inquisitive mind filled with opinions. She is not a “girly” girl, preferring to demonstrate her athletic prowess through her running. In addition, she values the phrase “practice makes perfect.” Because of her attitude, neighborhood interactions, and family responsibilities, she is a bit of a loner.
It is not until the end of the story that Squeaky changes to show a more understanding, accepting side to her personality, This occurs when Raymond completes his unofficial, but successful, run at the May Day race, and Gretchen comes in a close second to Squeaky. The reader sees Squeaky’s attitude change as Raymond shows his innate potential. He is no longer just her responsibility; he is her brother who has the ability to be a great runner. Also, Squeaky sees she can become friends with other girls. Although she may be selective, she thinks there is a possibility of being true friends with Gretchen.