Is Miss Caroline a victim or a villain?
I think that she is a victim.
She comes from Northern Alabama, which means that she is an outsider, so she doesn't understand the culture of the people in Maycomb. For example, she is clueless about the different status of the people in the Cunninghams and therefore the whole incident about Scout and Walter. She does not know that the Cunningham family is extremely poor, so when she wanted to give him money, Scout commented that she was shaming him. I think that after the first quarrel between Miss Caroline and Scout made her agitated and so, Scout might think that Miss Caroline is very mean to her because she doesn't like her. She was really depressed after that because she buried her head in her arms after the lesson. She is also a very nice person and very timid. She is scared a tiny weenie cootie that was on Burris Ewell's head.
Miss Caroline is a really nice teacher, it's just so that she is very inflexible and an outsider, so it is not her fault that she wanted to be mean to anyone.