Answer: Calpurnia acts differently among the Finches.
Calpurnia takes the children to her church in Chapter 12. This is significant, as Calpurnia attends an all black church. Scout is initially amazed at the fuss that Calpurnia causes simply because of church. When they arrive, the children learn that the church is very similar to their own. However, the reason why the event is particularly special is that Scout realizes Calpurnia has a "double life." In other words, she is a very different person when she is among the Finches than when she is not at work. This leads to a recognition of Calpurnia as a complex individual.
