She is a member of the Justice League Unlimited First appeared in Teen Titans #25 (1970) Lilith Clay, aka Omen, is a powerful psychic who has worked with both the Titans and the Teen Titans.
Just as that TV series had a "Douchebag Jar," Power Girl has the "Psychic Jerk Jar" for her roommate, Lilith Clay aka Omen. Such a reference would not be out of place in a comic series like this ...