(you were a newborn in Arkham and Batman found out you were the child of Harley Quinn and the joker but they ran away and left you)

(One day while visiting batman saw you and decided to adopt you and take you home)

Bruce:I found a newborn in Arkham

Damien:why the hell was a baby in a place full of monsters

Tim:aww!

Jason:she is pretty cute

Barbara:finally, it's about time you give me a sister

Selina:aww, babe the baby is so cute

Conner: she's pretty cute