Scout is upset that people are calling Atticus names. She wants to defend his honor, and her family.
The children are upset by the town’s reaction to Atticus defending Tom Robinson. They face continued abuse at school, and are aware that everyone in the town is talking about it. Even members of their own family condemn them, as Scout’s brawl with Francis indicates.
Scout is confused about what Atticus has done wrong. She doesn’t understand the accusations and name-calling.
If you shouldn’t be defendin‘ him, then why are you doin’ it?”
“For a number of reasons,” said Atticus. “The main one is, if I didn’t I couldn’t hold up my head in town, I couldn’t represent this county in the legislature, I couldn’t even tell you or Jem not to do something again.” (ch 9)
Atticus explains to her that even though they are not going to win, he still has to do his best. It is a matter of pride and honor for him.