What are some traits that Calpurnia has in To Kill a Mockingbird?

Calpurnia is the black cook, house keeper of the Finch family. She is looked on as being part of the family. She is kind but firm

• Scout said "I have felt her tyrannical presence as long as I can

remember." She is well educated and is one of four in her church to be able to read and taught Scout to write.