Writer: Otto Binder
Cover Artist: Curt Swan, Al Plastino
Penciler: Al Plastino
Inker: Al Plastino

Supergirl, or Kara Zor-El, as we know her today, first appeared in Action Comics #252 as Kara Zor-El. A female superhero counterpart for Superman, however, appeared as early as May 1943 in Action Comics #60, “Lois Lane – Superwoman.” A “supergirl” was first imagined in Superman #123 in August 1958 when Jimmy Olsen wished upon a magic totem for an aid and companion for Superman. Superman #123 is generally considered the prototype for the character of Supergirl, though not her first appearance. Kara Zor-El first appears nine months later in April 1959 in Action Comics #252. Although “supergirl” appears again in Superboy #78 in January 1960 in “Claire Kent, Alias Super-Sister,” it is not Kara Zor-El. Despite her continued popularity and role in the “Superman family,” Kara Zor-El was killed off just 26 years later in Crisis on Infinite Earths #7 in October 1985. Although several other characters assumed the guise of Supergirl, Kara Zor-El, the original Supergirl, returned to DC continuity in Superman/Batman #8 in May 2004 in a 6-part storyline, “The Supergirl from Krypton.” Now, fifteen plus years later, Kara Zor-El has appeared in several self-titled Supergirl series and in DC’s television efforts, including CW’s Supergirl.

Source: Wikipedia