It used to be that they had to do at least 7 (kipping allowed), but that was when males and females had different PFT's (physical fitness test). Females used to be required to do a chin-up for as long as they could, a minimum of 11 seconds.
Now that females have to run the same exact PFT as the guys, they had to alter the test in order to be fair, so the minimum requirement for pullups was reduced to three...dead hang, absolutely no kipping.
As a female Marine, I saw only three females that could do three dead hang pullups...and I'll tell you what...those chicks were BUTCH...and just built like a guy.
Even in my best shape, I couldn't do more than 1 dead hang pull-up.
Female Marines should still have a sense of femininity in my opinion...the female recruitment and retainment lately must be as low as it can get.