How do the people at Cal’s church treat the children?

Calpurnia takes the children to the First Purchase African M.E. church, an all-black congregation. Calpurnia takes special pains to make sure they are cleanly-scrubbed and as perfectly dressed as possible on Sunday.

At the church, a black woman named Lula tries to tell Calpurnia that white children don't belong at the church. However, Calpurnia points out that it's the same God, and the rest of the congregation welcomes the newcomers.