As Princess Diana (Wonder Woman) made her first ventures into man's world it became readily apparent that she would need a guide to lead her. An expert in ancient Greek history and language Julia was chosen as Diana's mentor. Despite her frail nature Julia took part on numerous missions with Diana, battling the Greek god Ares and the ancient witch Circe. Julia also confronted the god Hermes over his demeaning and extravagant nature. During her stay in Themyscira, she was saved by an Amazon, Pythia when she was drowning and it turns out she had been blessed by the Amazon Inspiration granting her wisdom and strength. When Pythia journeys to the United Nations, they are still seen to be quite close. Eventually Julia is forced to ask Diana to move out because of the effect she is having on Vanessa, her daughter. This was later revealed to be partially a manipulation by Doctor Psycho.

Julia plays a mother role for Diana in man's world, surrogate for Hippolyta who must remain on Themyscira. Julia has been seen at times to defend Diana from attack (as at the hands of the Cheetah) or confront those giving her a difficult time, including members of the military and police officers.