Answer: her growing empathy for Aunt Alexandra.
Aunt Alexandra is a traditional woman who cares about what other people say about her. She constantly complains about Scout, who does not behave "like a lady." Scout is impatient with her aunt as well, getting annoyed whenever she is criticized. However, after Tom is killed, Aunt Alexandra shows that she actually cared about the trial, and that she can show empathy towards others. Scout slowly realizes that the aunt's behavior is due to how much she cares about her family. This causes Scout to find a new kind of respect for her aunt.