User blog comment:MelJandre18/Season 3 fanfic/@comment-112.201.147.190-20120630171045/@comment-1038387-20120630185912

Joker's Daughter isn't actually Joker's daughter. When she was introduced in the 70s, she was a Robin fangirl, who made ridiculously desperate attempts to gain his affection. She said her name was Duala Dent and, at various times, claimed to be the daughter of Joker, Two-Face, Riddler, and Catwoman (and probably more).

Later, Zero Hour and Countdown retcons established her as the daughter of Earth-3 inhabitants Three-Face (Evelyn Dent) and Jokester (though she for a long time went by Riddler's Daughter because her mom married the Earth-3 Riddler.) Duela hopped the multiverse (or rather, multiverses) and was all previous incarnations of the character.

She could be played as a crazed Robin/Nightwing stalker.