Mrs. Alexander is Christopher’s neighbor whom he reasons must be a good person because she likes dogs and treats her dog well. Although Christopher’s investigation constitutes their first meaningful interaction, Mrs. Alexander seems to understand him and communicates with him better than any of his other neighbors. Rather than dismissing Christopher when he does not follow her social cues, she tries different tactics to engage him. She is patient with his questions and gives him honest answers. When Christopher says he does not like yellow, Mrs. Alexander has the forethought to avoid giving him yellow food. She seems to have a genuine desire to get to know Christopher and refers to herself as his friend.

Mrs. Alexander’s revelation of the affair between Christopher’s mother and Mr. Shears marks a pivotal point in the novel. When Christopher asks Mrs. Alexander about Mr. Shears, she first urges Christopher to talk with his father about it. When he refuses, she explains the situation and how Christopher’s father probably feels about it. She wants to answer Christopher’s questions, but she does not want Christopher’s father to know she has been talking about his family’s secrets. Mrs. Alexander does her best to navigate the line between helping Christopher understand the context of his family’s distress and respecting Mr. Boone’s privacy.

Mrs. Alexander is a kind, well-intentioned neighbor and a catalyst for helping Christopher realize his own ability to navigate the wider world. Her positive reaction to Christopher leads him to make her acquaintance without the assistance of his parents or teachers. She believes him and never treats him like he is incapable. It is only after getting to know Mrs. Alexander—and the crucial information about his mother that she provides—that Christopher has the courage to go to London on his own.