who were calpurnia's children?

In chapter 12, Scout and Jem go to church with Calpurnia because Atticus is spending more and more time out of town. It is here that we get a glimpse of Calpurnia's private life. Cal is an older woman and has a son named Zeebo. He seems to be a grown man. I recall Zeebo is the one they call to pick the dead dog up. I don't believe any other children are mentioned.