Well this is terrific news - fans of Batman: Arkham Knight can play as Batgirl in the first DLC add-on for trilogy finale. If only the game wasn't in 'Early Access' right now for PC...
This story add-on includes a new location with multiple missions and side tasks, and Robin will join in at times. It takes place before Arkham Knight for obvious bound-in-a-wheelchair reasons. It's out July 14th.
Those who own the Season Pass at least get it July 14th while everyone else must wait until July 21st. It's priced £5.79 outside the frankly ridiculously priced Season Pass which is almost the cost of the main game. It's all rather moot for PC gamers right now who have been royally shafted with a broken mess. It was pulled from sale and could take months to re-release.
Batgirl: A Matter of Family has been developed by, who created the tragically bug riddled Batman: Arkham Origins, which remains with issues today.
Those who already own it are effectively playing Batman: Arkham Knight in Early Access. It's unlikely, though possible, that Batgirl: A Matter of Family will still launch for PC owners.