Come on, you guys all know who SUPERMAN is.
Stephanie struck up a quick friendship with Supergirl while fighting Toyman and Mr. Freeze. Toyman was working to eradicate New Krypton, and he attacked Supergirl and Batgirl with a giant composite Superman/Batman robot. Stephanie called in a code black to Oracle, which meant a threat of the highest priority. Babs called in Dick Grayson, who called in Superman.
Superman came and helped take down the robot. When Stephanie and Damian went to take down Toyman, they ended up getting frozen by Freeze's raygun. Before Freeze could do serious harm to the kids, Superman interrupted with an "Ahem. Freeze." When Dick asked if Toyman was okay (while Supergirl melted the ice around Steph with her laser vision), Steph said, "I think so. We didn't hit him that hard."
Superman interrogated Toyman, but Toyman began "kzzzt"-ing in the middle of his anti-Kryptonian rant, Steph said, "We definitely didn't hit him that hard" and Superman responded, "Just another one of Schott's toys" as Toyman was a robot double!