She is part of the grim pantheon of Set and will appear in the Stygia sourcebook and Faith & Fervour.
Essentially she is Set's bodyguard, devoted to defending Set, Stygia and the King of Stygia. She is noted for lightning swift aggression. Worshippers of Set who have Lightning Reflexes, Quick Draw and/or Improved Initiative often claim to have been blessed by Idris.
Though I must confess I just watched "Jason and the Argonauts" the other night, so my mind has turned towards gods and mortals and all that jazz.
Also, I've got to find a way to make a spell similar to the "Children of the Hydra's teeth" for Conan. I just really want to say, "Against the Children of the Hydra's Teeth there is no protection," as a GM once in my life.