Taken from Batgirl #0
The daughter of Police Commissioner Jim Gordon, Barbara Gordon was raised in Gotham City, knowing firsthand the dangers inherent in living there. A classic overachiever and determined student, she struck out on her own as Batgirl in an attempt to help both Batman and her father in their mission to protect the citizens of Gotham.
Quickly reined in by Batman and trained to be a more effective hero, Batgirl became a valued member of his team along with the first Robin, Dick Grayson. Tragically, Barbara's life was forever altered when the Joker shot her in her civilian identity while attacking her father. She was paralyzed from the waist down, and it seemed as if her time as Batgirl had been ended permanently.
But Barbara did not give up. Working herself to the absolute limits of her physical and mental abilities, in time she regained the ability to walk. Taking things a step further, she made the daring choice to retrain herself and return to patrolling Gotham City as Batgirl.
Her second chance at being Batgirl hasn't been wasted, as she's confronted several new foes as well as assisting against The Court of Owls' attacks on Batman. Batgirl has also been known to take on missions with her friend Black Canary and the Birds of Prey team.