Character Analysis
The Red Girl is, contrary to popular understanding, not a Marvel sidekick. Well, as far as we know— she does move to Anguilla and is never heard from again.
Instead, the Red Girl is a free spirit who climbs trees better than the boys, expertly plays marbles, wears dirty dresses and only bathes once a week. Annie idolizes this mysterious child. Unlike Annie's mother, the Red Girl's mother does not make her do anything she does not want to do. She's still allowed to be childish (read: masculine) and this makes Annie both super-jelly and super attracted to her:
One day, I was throwing stones at a guava tree, trying to knock down a ripe guava, when the Red Girl came along and said, "Which one do you want?" After I pointed it out, she climbed up the tree, picked the one I wanted off its branch, climbed down, and presented it to me. How my eyes did widen and my mouth form an "o" at this. I had never seen a girl do this before. All the boys climbed trees for the fruit they wanted, and all the girls threw stones to knock the fruit off the trees. But look at the way she climbed that tree: better than any boy. (4.4)
There's a bit of friction between the Red Girl and Annie that seems fraught with potential lesbian feelings… even more than Annie and Gwen's relationship. Rather than talking about her own glorious love for the Red Girl, Annie talks about how much she likes the way the Red Girl smells. This could be just the scent of freedom from washing, sure, but it could also be sexy pheromones. Kinkaid leaves this tantalizingly ambiguous.
The Red Girl also gives Annie an outlet for rebellion. Annie follows in the Red Girl's footsteps and starts gambling (sort of; she's just playing marbles) and sneaking into abandoned buildings.
Gwen temporarily falls to the background and the Red Girl assumes the primo friend position. Annie begins to lie and steal to meet up with the Red Girl and buy her trinkets. It's no secret that this activity is done, at least partially, as an out-and-out act of rebellion:
Just before we parted, she gave me three marbles; they were an ordinary kind, the kind you could buy three for a penny—glass orbs with a tear shaped drop suspended in the center. Another secret to keep from my mother! (4.9)
After Annie's mother discovers a marble Annie intended to give to the Red Girl during one of their clandestine meetings, she prevents her daughter from going out in the afternoons. Annie and the Red Girl never see each other again when the Red Girl moves away.