What an interesting topic and thesis!
The hyper-sexualization of women that occurs within the book is similar to how it occurred in the real world of the 17th century - women who had sex outside of marriage were considered hyper-sexual.
Several of the women in I, Tituba fit this bill, but let's look at Tituba and Hester. Both of these women have sex outside of marriage at some point and become pregnant as a result. Unfortunately, sex outside of marriage can and often did also include non-consensual sex (rape). In the case of Abena and Tituba we see that each has experienced this, as well. Women were expected to adhere to very strict roles within their community, including being models of faith and morality, and those who did not conform faced severe repercussions.
"In the late 1600s, trials for fornication and infanticide specifically directed at women increased"(Gender Roles in Colonial America).
An analysis of how society viewed Tituba or Hester as a hyper-sexualized woman would be appropriate, as their behavior and relationships with men in the novel could have caused them to be viewed as such.
Abena could be analyzed as a cold and unpleasant woman, or at least mother, in her relationship with Tituba. Because Tituba is the product of a rape, Abena cannot look at her daughter without connecting her to the way in which she was conceived. In fact, Abena does not really begin to enjoy any part of life much until Yao shows her love and she grows to love him back, but even this is short-lived. Her relationship with Tituba, however, is not close, affectionate, or loving. In many ways, both Abena and Tituba are victims of Abena's rape.