Kreia was infamous, as all of her students: Revan, Sion?, etc., ended up failures.
Traya is the name of Sith Betrayal... perhaps the Academy was founded in the Golden Age, and a series of teachings (Pain, Hunger, Betrayal, other secret yet-to-be-revealed teachings), and Traya was the name given to the Betrayer... or, maybe it was a "Power" referred to on Malachor V...
Atris is concerned for the above reasons.
I don't think she was Handmaiden's mom, but perhaps she trained Arren Kae... ??? :ph34r: