Digressions to posts are fun
As a guy I totally get why he wants her to act feminine. Acting feminine is doesnt have anything to do with being submissive. It is more to do with him being a guy and wants a girl to Dominate. Not sure why that should be strange even if you are gay but please enlighten me
To the OP. Hormonal issues or some other issue might play a part in her acting. Otoh you might need to put your foot down and be more firm. Not sure how you are doing things but since you are new to the "lifestyle" then you most likely have things to learn to get her "under control" so to speak.
Perhaps the greatest advice from me without knowing you more and your situation is to talk to her. Sit down and talk a good long open talk and learn what she wants and why she acts like she does.
Good Luck to ya
btw just like Oz. I wouldnt either put up with her acting like that.