In Chapter 13 of To Kill a Mockingbird, Scout remarks that "There was indeed a caste system in Maycomb...." She adds that her aunt Alexandra fits into this system perfectly as she is at the top of the social system. Her dress is according to what is expected of a lady, her actions are what is expected of a lady, and her speech is in accordance with propriety. She entertains guests, and expects her niece and her nephew to act according to social expectations.
Her Missionary Tea sees some of the more socially elite arrive at the house. Aunt Alexandra feels that she must make the teacakes, having forbidden Calpurnia to bake them. When she speaks to Scout, unlike her brother, Alexandra calls her Jean-Louise and demands that she wear a dress. After a time, she requests that her brother talk with his children, informing them about the expected behavior. In addition, she objects to Atticus's including Calpurnia into the day-to-day instruction of the children; Alexandra, in fact, she suggests that he dismiss her.
In contrast to his sister Atticus is uninterested in social position and social facades; for instance, he sits alone in church. As a concession to his sister, however, he reminds Scout of their family tree and the name that they carry. He does, however, insist upon good manners as he demands that his son read to and be considerate of Mrs.Dubose, who suffers.
Much more liberal and tolerant than his sister, Atticus defends Calpurnia as the teacher of Scout and a member of the family, and he explains that his defense of Tom Robinson is taken so that his children will not have to acquire "the usual disease" of Maycomb. His integrity, however, gains the respect of his sister, who does worry for Atticus when he begins his defense of Tom. She indicts the town:
"They're perfectly willing to let him do what they're too afraid to do themselves--it might lose 'em a nickel. They're perfectly willing to let hims wreck his health doing what they're afraid to do, they're ____"
Thus, Alexandra displays the loyalty that Atticus possesses, as well. Nevertheless, appearances are of much more importantce to Alexandra that they are to Atticus.