How does Harper Lee symbolize family in the novel To Kill a Mockingbird?

Authors create symbolism by referring to objects in such a way that the objects take on more than their literal meaning. Beyond objects, authors will often create symbolism by choosing names for characters based on symbolic meaning. In Harper Lee's To Kill a Mockingbid, one symbol representing family can be found in Calpurnia's name.

Not only is Calpurnia the name of the Finch's cook who acts as a surrogate mother for the Finch children, Calpurnia is also the name of Julius Caeasar's third and last wife before his assassination. Calpurnia became stepmother to Caesar's daughter Julia and is especially celebrated for her faithfulness. Caesar is known to have been a man who carried out multiple affairs, yet, despite his infidelity, Calpurnia remained loyal. She was so loyal that she sought to protect him by begging him not to go to the senate meeting when she had what she felt was a premonition of his death, a premonition captured in Shakespeare's play titled Julius Caesar.

Similarly, Harper Lee's Calpurnia can symbolically be seen as the stepmother of Jem and Scout due to how much Atticus relies on her to help him raise them. Often, Atticus must leave the children to her sole care when he is called away on business, especially business with the state legislature. Throughout the years, Calpurnia has faithfully remained loyal to the Finch family, just as the historic Calpurnia remained faithful to Caesar. Also, just as the historic Calpurnia is tempted to disloyalty due to Caesar's infidelity, Harper Lee's Calpurnia is tempted to disloyalty when Aunt Alexandra joins the household and, due to her racist beliefs, tries to convince Atticus to let Calpurnia go. Regardless, Calpurnia remains faithful by remaining, and Atticus shows his faithfulness to Calpurnia by telling Alexandra that Calpurnia doesn't leave the household until she wants to:

Alexandra, Calpurnia's not leaving this house until she wants to. You may think otherwise, but I couldn't have got along without her all these years. She's a faithful member of this family and you'll simply have to accept things the way they are. (Ch. 14)

The faithfulness symbolized by Calpurnia's name represents the closeness of the Finch family. The historic Calpurnia remained faithful to Caesar and her stepdaughter due to her ability to value family. Similarly, Calpurnia remains faithful to the Finch family while Atticus remains faithful to Calpurnia because they value family.