Lena Luthor

From Superman Wiki

Lena Luthor, also known with her altered last name as Lena Thorul, is Lex Luthor's little sister.

Pre-Crisis

Lena was Lex's little sister, who lived with their parents. When Lex became a criminal, she changed her name along with her entire family to "Thorul" out of shame.

Supergirl: Cosmic Adventures in the Eighth Grade

In Supergirl: Cosmic Adventures in the 8th Grade, Lena Thorul appears as a little girl attending the same high school as Supergirl. She appears to be a budding scientist.

She was nice, and a good friend; however, she was sensitive and easily angered, using her scientific prowess to do things such as removing everyone's meteor-given superpowers.

30th Century Version

A woman named Lena Luthor appeared at the head of Luthorcorp in the 30th century. Her family was no longer feuding with Superman's by this era, and she helped end the fight against Muto. (Superman 2999)