The first important character in The War of the Wall by Toni Cade Bambara is the unnamed narrator, a local teenager who serves as the viewpoint character through which the main elements of the story are seen.
The next character of major importance is Lou, the narrator's cousin, who appears a slightly older teen.
The painter lady herself is a central element of the story, the plot of which revolves around her painting a mural on a building wall. She is a cousin of Jimmy Lyons.
Although Jimmy Lyons died in Vietnam before the opening of the story, and doesn't actually appear in the story as a living person, he is the inspiration for two forms of art, his name, chiseled into the wall by Lou and the mural. He appears in both the opening and closing of the story.