Scout clashes with Aunt Alexandra for most of her early childhood. Scout sees her as stuck-up and thinks she does not understand children. After Aunt Alexandra comes to live with them, things actually get worse for a while because Alexandra tries to turn Scout into a lady by making sure she wears dresses, attends social gatherings of the ladies. She tries to encourage Scout to appreciate her heritage, but focuses at first on how the Finch family is better than everyone else. This is exactly the opposite of the teachings Atticus has given her. Atticus has taught her to respect everyone, no matter how poor or what race.
Aunt Alexandra does play a pivotal role in Scout’s coming of age though. As Scout matures, she comes to understand Alexandra. She realizes that Alexandra actually does not approve of some of the bigoted remarks that the ladies make, and that she does worry about her brother. Ultimately, it is their love of Atticus that unites them and allows Scout to see that Alexandra does come from a place of having Scout’s best interests at heart. She is trying to teach Scout how to survive in the world that exists, and Atticus is trying to teach her to change it, or at least not accept it. Ultimately, both are lessons she needs to learn.