When Rocksteady first revealed that gamers would be able to play as Batgirl in Batman: Arkham Knight, gamers and comic book fans wondered which Batgirl it would be as the orignal, Barbara Gordon, is currently in a wheelchair and going by her moniker, Oracle. Well, Rocksteady's Sefton Hill has confirmed that the Batgirl in the game is actually: [Click to reveal additional information]
Barbara Gordon. How this occurs is currently anyone's guess. In the New 52, Barbara undergoes an experimental surgery to repair damage to her spine and restore fulll function of her lower limbs.
Fans are now theorizing that the prequel DLC will be set after Arkham Origins but before Arkham Asylym and will adapt a portion of The Killing Joke, a 1988 graphic novel from Alan Moore and Brian Bollard which depicted the Joker capturing and severly injuring Barbra.