Wilma was captured by Oscorp Industries scientists at birth to be tested on because she had only three limbs. She was named by Oscorp scientists after a character in the classic television show, The Flinstones; Wilma Flinstone.
Former Oscorp scientist Curt Connors, at the time, was working on regrowing his own lost limb with the Lizard serum. Wilma, along with Fred, was one of the test subjects for Connors, while also being one of his go-to lab pets. When Connors injected Fred with the serum, he became rabid, eating Wilma.