It would basically go about how after she's found accountable for her father's apparent death during their fight in her debut she is sent to Arkham academy with the the group of child's of villain and young criminals that form the class in the comic.
From there she has to form alliances and even some friendships to figure out how the place works, escape, and more importantly to her, put an end to the plans of the court and bring them to justice to prove that she's much more than a villain in training.
I think it would be really interesting to see the contrast between David Caldwell alias "Scorn" who basically has no interest and holds some resentment to his villain father and had no part on his crimes. Enigma who is obsessed with hers and her dad has a connection with Stephanie's. And Stephanie, who hates her dad with a burning passion and he trained her mind to make her a part of his life of crime one day but tries to hide that deep down she feels guilty for playing a part on her dad's apparent death.
Maybe Tim could appear at some point, perhaps he wants to check on Stephanie and notices weird things on the archives of the academy and investigates from the outside while Stephanie and the rest already are leading a case from the inside. Maybe he gets himself captured under the false identity of Alvin Draper alias "Mr Sarcastic" to infiltrate the school and Stephanie immediately clocks that he is Robin and begrudgingly accepts to accept an alliance