Consider the roles and situations of female characters. Make lists of different aspects of the female character's place in the overall story. Include anecdotal scenarios that will back up a holistic thesis.
Look at the relationship of female characters to each other. Examine any discrepancies that might shed light on the overall role of females in the book.
Review the role of female characters in relation to their male counterparts. Literary criticism has its famous set of contrasts, for example, man vs. nature, nature vs. society, that set up points of inquiry. In this case, your fundamental contrast would be woman vs. man.
Look at the vocational roles of women in the literature. Much of literary criticism can be applied to the workplace. Studying the work that each character does provides a great starting point for analyzing the whole of the work.
Consider the attitudes of characters and how their world-views contribute to the eventual outcomes in the story. The goals of characters may or may not cause outcomes. Evaluate how "powerful" each character becomes.