The series is set in the era of pre-feminism. Peggy is swimming upstream in trying to make it as a copywriter in advertising. Megan had to marry the boss to have her ad ideas, such as for the Heinz account, taken seriously. Sally, Don Draper's daughter, needed a heavy dose of therapy to stop being self destructive.
However, all these women are amassing power in their own right. No, it's not made official. Peggy's name is not part of the ad agency's name. But she's there. She moved on from a degrading office affair to create her own lifestyle. If she's shrewd she'll align with Megan, not compete with her.
Lawyers who are afraid they won't make partner or even have enough work to do practicing law can study how the seemingly marginal get what they want from the system. The women of "Mad Men" show that it's irrelevant what the status quo is. What matters is individual action, without a hint of self consciousness.