Ellie Leeds was a young girl from Midvale, the daughter of local S.T.A.R. Labs scientists Jerry and Donna Leeds. Unbeknownst to everyone, she was the first to discover Supergirl's arrival, but was exposed to X-Kryptonite and fell into a coma. When she awoke years later - after a chance meeting with Supergirl - she started exhibiting Supergirl's powers, and also believed she was the Girl of Steel. This made her the target of an industrial spy. Supergirl and Ellie defeated him. With the effects of the X-Kryptonite over, Supergirl was able to make Ellie's recovery permanent. The family moved to a S.T.A.R. facility in Florida.
- 1 Appearances of Ellen Leeds (Earth-One)
- 1 Images featuring Ellen Leeds (Earth-One)
- Quotations by or about Ellen Leeds (Earth-One)
- Character Gallery: Ellen Leeds (Earth-One)