She developed a notion of gender, in which women conformed to an expected role in society, which men controlled e.g. that they should nurture children, which is learned as girls.
This led to the idea of the “Other” in which men defined women as fundamentally different from the norm and inferior to them.
Progress could only be made if they became conscious of their own identity, through self-liberation and escaping from a domestic and family role imposed on them by men.