I have personally seen female pilots who were just as good as their male counterparts, and I am one of their biggest defenders. I love my sister Marines just as much as my brothers and have the utmost confidence in them, but I can't say I buy into that statement. 9+ would have anyone heaving and blacking out, if sustained for more than a few seconds.
It's not quite that simple. Women generally can survive and tolerate more continuous G-force than men, but male pilots can generally continue to perform the duties of pilot better than female pilots following intermittant exposure to high-gee, as in violent aerial maneuvering- dogfighting.
But much also depends on the physical condition of the pilot, the angle of the seat, and currency [recent exposure] to such conditions, just one reason why current flight training is all-important. Female pilots also exhibit less tolerance for g-forces during during menstruation, though some interesting studies suggest that in early stages of pregnancy, their tolerance mat exceed that of most men. But those are all generalizations, and it's the individual's performance that counts, to about the same level as that of an Olympic athlete.
See the article on *the Spin Doctors* from the USAF Airman magazine for additional interesting info, particularly regarding the present generation of G-suits and plans for the forthcoming ATAGS flight suit, and the information *here*.