Complex sentence: She argues that black female sexuality (from the 19th century to present) was formed in exact opposition to that of the white woman's, and that historically many black feminists have failed to develop a concept of black female sexuality.
Split into simpler sentences: She argues that black female sexuality (from the 19th century to present) was formed in exact opposition to that of the white woman's. She notes that historically many black feminists have failed to develop a concept of black female sexuality.