Do you mean Supergirl, Superman's cousin? If so, Kara Zor-El, Kara to her friends.
Diana Prince
Superman's alter ego is Clark Kent. Clark Kent is the civilian persona adopted by Superman when he is not saving the world.
The Flash's alter ego is Barry Allen. Barry is a forensic scientist who gains super speed after a chemical accident and becomes the superhero known as The Flash.
Steve Rogers is the alter ego of Captain America.
An alter ego is an alternative identity of a person, or a close and intimate friend.
Batman is Bruce Wayne's alter-ego.
Spaceman Spiff's alter ego is Calvin.
tony stark
Spaceman Spiff's alter ego is Calvin. (from Calvin and Hobbes)
Darth Sideous' alter ego is Emperor Paltapine.
Alter Ego - soundtrack - was created in 2007-06.
Superman's alter ego is Clark Kent reporter