A female warrior is called a warrioress.
There are also other terms for a female warrior which include Valkyries, Onna-musha, Shield maidens and Amazons.
Warrioress is the most common term and generally accepted term for a female warrior.
Amazons in Greek mythology, Amazons were a mythical race of female warriors.
And the Dahomey Amazons, which is a real life all female military regiment in West Africa, were also named after this mythical race.
Onna Musha in Japanese culture were female samurai or warriors.
Shield maidens in Norse and Viking mythology, shield maidens were female warriors often associated with the Valkyries.
Valkyries in Norse mythology were female figures who escorted fallen warriors to Valhalla.
And depending on the culture and the historical period, female warriors may even even referred to as banlaoch in Irish or Gordafarid in Persian literature or have other specific names.