Aunt Alexandra and Calpurnia, or Cal, are both strong-willed figures who play significant roles in the lives of the Finch children, Jem and Scout. Both are firm in their beliefs and want what's best for the children. From there, however, the differences between the two women are more compelling. Calpurnia, the Finch family's African American housekeeper, has acted as a surrogate mother to Jem and Scout for a considerable period of time and knows the family as well as anybody in Maycomb. Hers is a welcome presence for Atticus and his kids. Aunt Alexandra, previously a regular visitor to the Finch household, becomes a full time member of the household when she moves in with the express intent of imposing a more austere form of discipline on the children, especially on Scout, whom she views as insufficiently feminine.
From the beginning of Harper Lee's To Kill a Mockingbird, the story's young narrator, Scout, is very explicit in her dislike of her aunt, contrasting Alexandra with her father by commenting that "I was sure that she was swapped at birth and that my grandparents had gotten the wrong child." Whereas Calpurnia is open-minded about people, choosing to judge on the basis of character rather than ethnicity, Alexandra is the exact opposite, condemning young Walter Cunningham because of his background and exhibiting serious reservations about her brother's decision to defend Tom Robinson, the disabled African American man accused of raping a white woman. And, as noted, Alexandra is adamant that Scout act more like a girl and less like a boy, including addressing the latter by her formal name, Jean Louise.
Calpurnia and Alexandra are similar only in their love for the Finch children, and are both strong, independent women. Beyond that, they are as different as night and day, with Calpurnia exhibiting the more admirable qualities.
Aunt Alexandra is Atticus Finch’s sister, while Calpurnia is the Finch’s African-American cook and housekeeper. These two characters both share similar qualities, but differ in many aspects. Calpurnia is not related to the Finchs like Alexandra is, and since she is black, she occupies a lower social status. Calpurnia is able to provide the children with valuable insight from an African American point of view, while Aunt Alexandra is concerned with conforming Scout into the stereotypical Maycomb female. Calpurnia sees eye-to-eye with Atticus when it comes to childrearing, and displays more sympathy for the children when they misbehave. In contrast, Alexandra often disagrees with the way Atticus is raising his children and shows less sympathy towards Scout because she disapproves of her “tomboyish” lifestyle. Calpurnia and Aunt Alexandra are both strong female figures who play the role of mother for Jem and Scout. Both characters rule with an “iron fist,” and make sure that the children do not get into trouble. They both have Jem and Scout’s best interest in mind, yet convey their feelings and beliefs differently.