You were sent to Arkham with your father before Bat man decided it was too hard for you, you didn't say anything, always be quiet and do what they ask. In the Batcave, when you are sitting in the Batcave, listening to the bat family arguing whether you should stay or not, an old man suddenly shouted

"WHY IS SHE HERE!? SHE'S THAT CLOWN DAUGHTER THAT CAUSES ME TO BE IN HELL ALL YEAR!!" you immediately know who he is, Jason Todd