In pre-New 52 continuity, Duela Dent is from Earth-3, she is the daughter of Three-Face and Jokester. She was part of The Riddler Family, with the Riddler as her step-father.
Duela Dent first appeared baffling and confounding Robin. Calling herself the Joker's Daughter, and dressing in his distinct purple pin-striped suits, she vowed to Robin that she would figure out his secret identity while he tried to figure out hers. In the following months, Robin would meet various masked female opponents claiming to be the daughter of some of Gotham City's more illustrious criminals, like the Penguin, Scarecrow, Catwoman and the Riddler. Robin would ultimately find out that it was actually Duela Dent each time they crossed paths.
Major Story Arcs
Duela was able to determine Robin's real identity, Dick Grayson, and used this knowledge to get his help in joining the Teen Titans, a team of teenage superheroes in which Robin was a member. She claimed she wanted to atone for her father's crimes. Duela also revealed her real name and that she was actually the daughter of Two-Face. She explained that she wanted to join the Titans to make reparations for her father's criminal behavior. Duela Dent created the identity of the Harlequin and donned a new costume when she joined the team, but was only a member briefly before the Titans disbanded. For a short time, she called herself Card Queen and eventually showed up at the wedding of Donna Troy without a mask, looking much older, and revealed that she was too old to be Two-Face's daughter. She disappeared during the events of the Crisis of Infinite Earths.
The Harlequin has exhibited delusional and psychotic behavior, taking delight in confusing everyone about who her infamous parent is. She became an ally of the Teen Titans when they were forced to face the Justice League Of America. Duela Dent eventually joined the Titans East simply because she was asked. She fought alongside her team until Raven asked if Duela wanted to joins the Teen Titans instead. She accepted the invitation and clubbed Enigma on the head, assisting Raven. Duela Dent was a member of the Teen Titans before she was killed by one of the Monitors , due to her being an anomaly in the present DC Universe. A contingent of Titans, including Donna Troy, Jason Todd, Robin, and Nightwing have made it their purpose to avenge Duela Dent.
The Joker's Daughter made her New 52 debut in Catwoman #23, with an account of her origin recounted in Batman: The Dark Knight #23.4 - The Meat & the Marrow. While she is named Duela, her surname is never confirmed. The daughter of an affluent Gotham couple, Duela demonstrated some disturbing tendencies at a young age, which were exacerbated after her father secretly killed her pet pug. She became anorexic and began self-mutilating. After cutting her face, Duela received plastic surgery, but during the procedure she twitched too much under the surgeon's scalpel, further damaging her face. Eventually, she ran away from home to the Gotham City's Nethers, an underground cave system populated by escapees from Arkham Asylum, with Cat, her new pet. At some point following the Joker's recent return, Duela found his face/mask, and donned it, becoming the Joker's Daughter. She freed the women of the Nethers from their cruel subjugation from that area's men. She was on hand at the Crime Syndicate's meeting in Forever Evil #1 - Nightfall.
Powers & Abilities
In Pre-Crisis continuity, Duela Dent used outrageous gimmicky weapons, including a pipe that blew explosive or sticky bubbles. She also had a lipstick tube that shot bullets and a giant powder puff that stunned and confused enemies. In Post-Crisis continuity, Harlequin seems to have a degree of agility and fighting skills, as well as being psychotic.
Duela Dent has appeared in Tiny Titans.
Duela Dent is the daughter of Jack "The Joker" Dent.
In the alternate timeline of the Bombshells, Duela Dent is a Nazi advisor on matters magical, having worked up some expertise with subduing and nullifying the powers of magicians. She runs a cabaret entertainment venue, where she has forced both Zatanna and Raven to perform for her own amusement and that of Nazi soldiers. Her goal is to force her captives into accepting their place as her servants using both intimidation and false love. Zatanna resisted for too long and was banished into the Jewish Ghetto to act as a trojan horse as the Jokers Daughter disguised herself as Raven in order to be lead to the others. Raven in the meantime had also resisted Duela for too long and before the capture of Zatanna been placed into a deep sleep along with attempting to brainwash her into doing Duela's bidding.