In chapter three, Jem invites Walter Cunningham Jr. over for lunch, and Scout is appalled when she witnesses him pour gravy all over his meat. Unfortunately, Scout does not hold her tongue and comments on Walter's strange eating habits, which embarrasses their guest. Atticus subtly attempts to stop Scout from commenting on Walter's eating habits, and Calpurnia ends up requesting her presence in the kitchen. Once Scout enters the kitchen, Cal proceeds to chastise Scout for her rude, disrespectful behavior. Cal also explains to Scout that Walter Jr. is their company and that she should go out of her way to make him feel comfortable. Scout responds by saying that Walter isn't company and that he is just a Cunningham, which infuriates Cal, who proceeds to spank Scout before sending her back into the dining room.
After lunch, Jem and Walter Jr. return to school as Scout attempts to persuade Atticus to get rid of Calpurnia. Scout accuses Cal of favoring Jem and believes that Atticus should fire her. Atticus responds by defending Cal and tells Scout,
Have you ever considered that Jem doesn’t worry her half as much?...I’ve no intention of getting rid of her, now or ever. We couldn’t operate a single day without Cal, have you ever thought of that? You think about how much Cal does for you, and you mind her, you hear? (Lee, 25)
Atticus recognizes the importance of Calpurnia and views her as an integral member of their family. Cal acts as Jem and Scout's surrogate mother and is quick to correct their behavior when they get out of hand. Later on, Atticus defends Cal again when his sister suggests that he get rid of her.