The thing about naginata being associated with female warriors comes from centuries after the Genpei War and was superimposed on the semi-legendary Tomoe in prints and festivals from the 19th century onwards. The Heike Monogatari simply states that she was skilled in the weapons of a mounted warrior of the time - bow and tachi sword:
"Tomoe was especially beautiful, with white skin, long hair, and charming features. She was also a remarkably strong archer, and as a swordswoman she was a warrior worth a thousand, ready to confront a demon or a god, mounted or on foot. She handled unbroken horses with superb skill; she rode unscathed down perilous descents. Whenever a battle was imminent, Yoshinaka sent her out as his first captain, equipped with strong armor, an oversized sword, and a mighty bow; and she performed more deeds of valor than any of his other warriors."
The Heike Monogatari is a war tale as a work of literature and many historians cast doubt on her very existence. However for gaming she is a great asset in what is the classical heroic age of samurai Japan - their equivalent to Homer.
That being said, not sure if you looked at the Old Glory/West Wind offerings I mentioned? The photo isn't too clear and can't vouch for their quality myself but the "Tometa" figures at the top (represented separately on horse and foot) seems to based on the modern conception of her.