Element Girl originally a supporting character for another superhero. However, she managed get herself several re-imaginings.
Urania Blackwell was a secret agent working for the American government. She duplicated the events that gave Metamorpho his powers in order to gain powers herself. Elemental Girl found Metamorpho and tried to strike up a relationship with him. However, Urania constantly fought with Sapphire Stagg (Metamorpho's human love interest). In the end, Metamorpho ultimately chose Sapphire. Afterward, Urania lost touch with him.
It turned out Element Girl lost her job for being too conspicuous (due to her monstrous appearance). She became depressed and isolated herself. When she attempted to kill herself, her body adapted to survive. Death of the Endless told her to ask the source of her power, the Egyptian god Ra, for death. When she does so, Urania died (by being turned to ash) with an expression of joy.
Flashpoint and New 52
A new version of Element Girl appeared in Flashpoint. This version is called "Element Woman". Emily Sung (Element Woman) was among the heroes that helped Cyborg fight Wonder Woman and Aquaman. She was shown to have a crush on Cyborg. She met S.H.A.Z.A.M. (six kids each with one of the powers of Captain Marvel) and decided to protect them. In the New 52 universe, she helped Cyborg fight Ocean Master and joined the Justice League.
Emily has a childish and socially awkward personality. In fact, during a battle, she offered people juice boxes. Despite this, she managed to join the Justice League.
Both versions have the same powers as Metamorpho. They can turn their bodies (or any part of it) into any element in the human body. They can also reshape their body into various shapes (similar to Plastic Man) when using the before-mentioned power.
Showcase Presents Metamorpho volume 1