Wuthering Heights was written at a time when women's rights as we now know them were virtually non-existent. Women were consigned to a subordinate role in society, expected at all times to defer to the men in their lives; their husbands, brothers, and fathers. Nevertheless, despite their social impediments, the female characters in the story still manage to display a good deal of strength and independence, each in their own individual way.
Of course, inevitably, there's a limit as to how independent these women can be. Even the wild, unruly Catherine is gradually tamed by society's norms. No longer able to roam free, she is confined to a stultifying, loveless marriage, with all the restrictions that that entails. This is simply one of many situations in Catherine's life in which she's been the victim of patriarchy. It says a lot about the status of women in society at that time that Catherine is only able to enjoy any degree of independence when the men in her life die off.
Thank goodness, then, that the figure of Nelly Dean is on hand to show the way. She acts as a reminder of what's possible for a woman if she's given the opportunity. Though very much at the bottom of the social scale due to her employment as a servant, Nelly is set apart from the other female characters in the story due to her maturity and perspective. This critical distance gives her a unique, if somewhat partial, glimpse into the lives of others and shows us how it is possible for a woman to transcend the numerous limitations and social restrictions imposed upon her by society.
Women in Wuthering Heights have a couple of roles. First, they show the typical lot of the woman in the novel's time period. As a female, one can either be a houseworker or a wife. As we can see, all the women occupy these roles: Catherine, Cathy, Isabella, Frances, Zillah, and Isabella. They also give insight into the accepted norm that the man essentially owned all the woman's property, even the woman herself. Heathcliff's actions towards women show that wives can do little about their husbands abuse; husbands are rarely held accountable for these actions.
Another, deeper insight into the presentation of women can be found in the duality of characters. Catherine and Isabella initially show the differences in how daughters are raised from Wuthering Height's household to Thrushcross Grange's household with Isabella standing as the typical and accepted manner in which to raise a daughter. This sets up Catherine's eventual choice of Edgar over Heathcliff. Furthermore, the similarity between Catherine and her daughter Cathy is shown in the relationship that Cathy has for Hareton which parallels the one her mother had with Heathcliff.