All highborn women were samurai.
This is obviously not true, but it's probably irrelevant anyway.
Chances are the protagonist is an Ainu woman taking revenge on Japanese invaders.
IIRC Hokkaido only became a formal part of Japan after being annexed in the 1800s. The ethnic Ainu are actually a mix of Mongol and Chinese colonizers/invaders who probably also took northeast asians, perhaps as slaves, there (Vietnamese, Burmese, etc.).
I don't know what Ainu gender roles were, but if they were closer to the Mongol and Chinese then they should be very different from Japan.
Ghost of Yotei's protagonist being female should be rather accurate, if we're to trust in Insomniac as much as they deserve for Ghost of Tsushima.
Of course, this doesn't change the fact that the main character's voice actor is a toxic piece of shit who should have never been considered for the job.
But one should be able to discern the art from the artist, IMO.