Batgirl: A Matter of Family is one of the Arkham Episodes from Batman: Arkham Knight, a prequel story that takes place before Batman: Arkham Asylum, in which Barbara Gordon suites up and teams up with Robin to save her father, Commissioner Gordon, who has been kidnapped by the Joker. It was released for Season Pass owners on July 14, 2015 and was released for the general public on July 21st, 2015. Getting the DLC unlocks Batgirl for all Challenge Maps.