1.When Jem reveals that he knows about his cousin Joshua, who "went around the corner at the University, she gets angry. She is dissatisfied that the skeletons in the Finch closet have been discovered by Atticus; so she makes Atticus impress the kids that they are not from" run-of-the-mill people.(btw I think this is in chapter 13)
2.He eventually becomes more sensitive about things and more aware about the things happening around him. He gets angry also about the changes. I guess you can say that he is a dynamic character as most people like to call him.