Calopurnia and Miss Maudie both represent female role models for Scout in divergent ways. Calpurnia is black, which makes her different from the Finches because of the way in which race is viewed in Maycomb at the time. However, because she has taken care of the children for so long, she has become almost like a mother to them. The children are able to see past her skin color and see her only as the caring woman that she is, someone who will protect them when their father is not around and who fulfils the role of a mother nicely. Because they learn to see past her skin color, they are in a much better position to see past Tom Robinson's skin color as well and to see him as the innocent man that he is. Because of this, they are even more startled by the outcome of the trial and it gives them a glimpse into the adult world of hatred and prejudice. They do not like what they see, and rightfully so. This is how change is made in future generations.
Miss Maudie is also a female role model. She is a widow, like Atticus, and in some ways acts as his other half even without a romantic entanglement. She is highly critical of the hypocrisy in the town, particularly of the so-called church goers - and she is not afraid to share her wisdom with the children. Her views align with what they have already learned from Atticus. As a result, her position in the story is to act as a codification of the values that the children are learning from this experience.
Calpurnia is the family's black housekeeper and has raised Jem and Scout and in many ways acted as their mother since their mother passed away four years prior to the beginning of the story. She serves as a bridge between the worlds of black and white and also provides a great deal of love and support for Jem and Scout while also providing discipline and tough love when necessary. Her place is a very respected one and obviously different in some ways because she is not in fact their mother. Her devotion to the children is unquestioned and very impressive.
Miss Maudie Atkinson is a neighbor of the Finches and a close friend of Atticus and his children. Like Atticus, Miss Maudie is actually a widow, and she has grown up in Maycomb with the attorney and his brother, Jack. Her favorite pasttime is gardening, and Scout also recognizes her for baking the best cakes in the neighborhood. Maudie speaks her mind honestly and clearly, and she exhibits a sense of humor several times in the novel. When Miss Maudie's house burns down on the night of the early snow, she seems to be less concerned than most. She moves in with fellow neighbor, Miss Stephanie Crawford, until the house is rebuilt.
Calpurnia is the housekeeper. She has been around since the death of Scout's mother. Like the previous editor said, she serves as a surrogate mother. When Scout makes fun of Walter Cunningham at the diner table, Calpurnia disciplines her.
Scout and Calpurnia lock heads often. Calpurnia tries to teach Scout manners and self-discipline. Scout resent it and tells Atticus on Calpurnia but Atticus keeps Calpurnia on duty.
Calpurnia is protective of the children. This was evidenced when she had seen the rabid dog and also when she felt the need to protect the children.
Calpurnia was the cook within the house and when the kids were young also helped raise them in absence of their mother. She is helping the kids as they grow older and Atticus placed her within the household. When Aunt Alexandria questioned her about why she was in the household, Atticus defended her because she was the right person to be there. She is protective of the kids and serves as a bridge between white and black.