Injustice: Gods Among Us Year 2
Harley reveals to Black Canary that she has a four-year-old daughter named Lucy who is being raised by her sister. After discovering she was pregnant, Harley left the Joker for almost a year to have their baby, instead of abortion. She decided to give her up because she knew the Joker would never want a daughter and bringing her into their life would be dangerous. When Harley returned to the Joker after being gone so long she thought it was a joke that he hadn't even noticed she was gone.
As a young child, Lucy liked to put tutus on her toy cars, much to Harley’s amusement.
It is unknown if the Dee Dees from “Batman Beyond: Return of the Joker” are her daughters or not. It is also unknown if she inherited her parents’ mental health problems.
Injustice 2 Comic
Lucy makes a cameo appearance in her mother's ending. It's revealed that she only knows her mother as her "crazy Aunt Harleen", but someday Harley will tell her the truth. Her father doesn’t know she exists.
She is blonde in the game, but a redhead in the comics.