>>91426749Well it probably isn't anyone we've met before. Not in the in the series proper, at least
Jack's been on his own for fifty-some odd years, meaning most of his affiliates from Season 1-4 are either older than dirt or dead. Wouldn't make sense to shoehorn someone in, not with only having ten episodes to tell the story. Genndy isn't one for backpedaling.
Maybe she was one of the thousands of children present for Aku's fairy tale readings? Who knows.
My personal belief is the High Priestess is actually
TeacupBallerina, who managed to meme herself into the Samurai Jack universe through sheer lust alone. 
