Because Scout is motherless, Atticus knows that she must have a feminine influence and leaves that task to several women whom he trusts. Each influences Scout in a different way.
Calpurnia: Calpurnia is a true mother figure to Scout. She takes care of her daily needs, helps teach her to read, disciplines her, and even shows her off at church. From Calpurnia, Scout learns that Southern ladies are tenacious and protective. She watches Calpurnia's reaction when the rabid dog comes near Jem and her; she realizes (as part of her maturation) what Calpurnia has had to endure not just as a woman but also as a black woman living in the South. Finally, she learns from Cal what it means to show hospitality as a Southern woman, especially from Cal and her church's response to Attitus's defense of Tom.
Aunt Alexandra: Scout learns from her aunt what it means to be a gracious lady even when people make distasteful comments in one's home. The tea party at Atticus's house is a good example of this. Aunt Alexandra maintains her poise even though the other "ladies" are speaking badly about her brother. Scout also learns from her aunt that even the most stubborn, set-in-their-ways Southern women can change, hence, her aunt's changing perspective toward the Tom Robinson case as the trial ends.
Miss Maudie: Scout learns from Miss Maudie that sometimes Southern ladies need to be bold, especially in defense of their friends and family. At the tea, Miss Maudie does what Aunt Alexandra does not feel she can do as a hostess by putting the other ladies in their place by running down Atticus at his own table. Scout also learns from Miss Maudie that true Southern ladies don't gossip or prejudge others.