Chapter 9 begins to really offer insight into the characters. For example an excellent example of characterization is how Atticus shows that he is a patient man by nature in the way that he deals with Scout not wanting to go back to school.
Scout's characterization is shown by her reaction to the teacher who doesn't want her to read at home anymore, her attack on Cecil who calls her father names, and in the way that she has to deal with her cousin. All of these show that she is fiercely loyal to her family and her father, in particular. She does not conform as others do as she refuses to dress like a proper girl would.
Jem's characterization happens a bit later when he stands with his father against an angry mob. This shows that he has matured and decided that he wants to be a good man like his father. He wants his father to be proud of him, but he also knows what it feels like to be truly proud of onesself.