There are many roles that women play in the novel To Kill A Mockingbird. In light of this, let me offer a few of them.
First, Calpurnia functions as a mother to Scout and Jem. As you probably know, their mother died and so Calpurnia, even though a housekeeper, functioned as a surrogate mother. She loved them, disciplined them, and kept them respectful and "straight." So, in Calpurnia, we see an example of leadership. I should add that she is also educated and respected - especially by Atticus.
Second, we have Mayella. She functions in the opposite way in terms of role. She grows up in a horrible situation as a child of Bob Ewell. She is abused and neglected. So, when she comes onto Tom Robinson and she is detected, she resorts to lying and an honest man is condemned. She functions as a victim who cannot bear to live with her shame.
Third, we have someone like Ms. Maudie. Her role is one of wise counselor. She sees things others do not. In many ways she is like Atticus. She has a good moral compass. She is also kind and compassionate. And she is always insightful.
In the end, women play no single role. They function in various ways.