The end of chapter 24 is the first time when Scout realizes that Aunt Alexandra has a heart. She's worried sick for Atticus and his health during this trial. Aunt Alexandra more importantly shows Scout the true meaning of being a lady. It isn't about gossiping circles of women: it's about a woman keeping her cool when things get tough. Scout sees her hold her head high and move on as if nothing has happened, when she could've run into the room spreading the word of Tom's death.
Miss Maudie shows Scout another form of being a lady. When Miss Merriweather begins to criticize Atticus in his own home in front of both Alexandra and Scout, Miss Maudie shuts her up with (along the lines of) "his food doesn't stick going down, does it?" Her icy demeanor and confidence put Miss Merriweather in her place and she says no more. She does not stand and she does not raise her voice. But she gets her point across quickly.
As for Calpurnia, she had two major influences on Scout. First she acts as a mother when young Walter came to eat lunch in chapter 3 by correcting her and spanking her for not treating Walter like company. (no matter how he eats his lunch)
The second influence occurs at Cal's church in chapter 12. There she shows Scout (with Lula) that she has to live two separate lives: she is an educated woman, but she is also a black woman. She must respect both "worlds" and those in them.