More to the point of the matter is what YOUR ATTITUDE -- be you woman, man, girl or boy -- is TODAY.
Most MEN and BOYS who practice martial arts (at least in the U.S.) are warrior-wannabees, and are a joke to the true discipline of martial arts ethos and practice.
I.e., martial arts (or war) are hardly gender exclusive. The criterion of a truly good warrior is what resonates in his/her spirit, mind, and intentions -- a rare depth of character and integrity in the individual which, correspondingly, expresses itself through his/her physical prowess.
As to the existence of women warriors in history, it is well to remember that history is written by its victors. I.e., "history" is biased in favor of those who wish to keep silent those who question or, by their mere presence, threaten the status quo.
As such, in societies hostile to true individual female autonomy and power, history would hardly acknowledge the existence of such women warriors. invisible. But, given the desire for the human spirit to be free, no matter the culture, no matter the circumscribed codes of a given community, there are undoubtedly girls and women among the rest who dare question the restrictions imposed upon their sex, who will, at great cost, struggle (however tacitly, however discreetly) to break free.
That said, who is anyone to say, definitively, that -- in the absence of archaeological/anthropological evidence to the contrary -- no female warriors ever existed in Japan (or elsewhere), and in whatever form or manner of subterfuge such a girl or woman may have been required to live/fight as she saw fit and consistent with her inner reality and experience.
(Nice point, by the way, by a previous posting, on the matter of the West African tribe of women warriors.)
Have a little more guts, people. The world is what you make of it.