Batwoman makes her first appearance in this book, and her third appearance overall, in World’s Finest 90 (Sept/Oct 57), in a story by Hamilton, Sprang and Kaye.
Elton Craig, who appeared a couple of issue earlier, has one remaining kryptonite-infected super-power pill. Superman and Batman are on his trail, and Kathy Kane decides to join the hunt as Batwoman. The heroes tell her to go home, but she doesn’t listen, and, in fact, finds Craig first. She stops him from taking the power pill by taking it herself.
The heroes continue to disparage her, telling her that having powers will be too dangerous for her, and once again insisting she go home. She vows that she will use her powers to discover their identities.
Although she fails at achieving that, she impresses Superman with her skills. Superman must have had a private chat about Batwoman with Batman before the final scene, because Batman finally agrees that Kathy has earned the right to continue being Batwoman.