Aunt Alexandra has an agenda when she comes to live with her brother Atticus in Chapter 13 of To Kill a Mockingbird. Most of that agenda is to teach Jem and Scout to respect themselves and the family ancestry from which they hail. Alexandra thinks that Jem and Scout run wild and should behave in a way that shows they are "Fine Folks." Scout explains that there is certainly a caste system in Maycomb and that Alexandra wanted to teach them about their heritage so they would honor it through their behavior. Scout explains as follows:
"I never understood her preoccupation with heredity. Somewhere, I had received the impression that Fine Folks were people who did the best they could with the sense they had, but Aunt Alexandra was of the opinion, obliquely expressed, that the longer a family had been squatting on one patch of land, the finer it was" (130).
Aunt Alexandra's teachings didn't seem to be sinking in as she would have liked, so she sends Atticus in to talk to Jem and Scout--hoping that will help. Atticus explains as follows:
"Your aunt has asked me to try to impress upon you and Jean Louise that you are not from run-of-the-mill people, that you are the product of several generations' gentle breeding. . . and that you should try to live up to your name. . . She asked me to tell you you must try to behave like the little lady and gentleman that you are. She wants to talk to you about the family and what it's meant to Maycomb County through the years, so you'll have some idea of who you are, so you might be moved to behave accordingly" (133).
All of these teachings happen before the trial of Tom Robinson. Many people in Maycomb are saying horrible things about Atticus and the Finches as a family. Alexandra wants to preserve their family name because they are good people. She also wants the kids to act appropriately to protect them and to protect the long-standing, good reputation of the Finch family which has existed in the county for many generations. After these two main teaching moments, Alexandra continues to teach the kids about respecting their heritage and proper behavior by being in the home, correcting them as needed, and providing a good example of "Fine Folks."