Name: Rosalina Marshall
A

ge: 14 
Eye color: Purple
Hair color: Dark brown
Likes: music, cartoons, electronics, acrobatics, comedy, pie!!!
Dislikes: Snobby people, when people cry, feeling vulnerable, bullies, teachers, being trapped, and being grabbed.          
Family : little brother,  Benjamin
Location: Gotham city orphanage
Alternative identity: Nightshade

Short bio:
Her parents abandoned her and her brother when she was nine and he was two. They were dropped off at Gotham orphanage. One day when she (she was 10 at the time) was walking "home" from school someone grabbed her, pulled her into a van, and drove off. They drove to Joker's hideout where her brother (he was only three but was very smart) and other children were tied to chairs and a camera was set up in front of them. The camera was broadcasting everything live to Batman and the rest of Gotham. Instead of tying her up like the others the goons took her to a ledge above a vat of chemicals, while the Joker ranted and laughed at the camera. "Pay up Bats' or the girly up there gets a bath HAHAHAHA!!!" the Joker laughed. After about a minute with no Batman, and Rosalina struggling to break free from the grasp of the two goons that were holding here up, the Joker demanded them to throw her into the vat below.
(I'm lazy and planning to make a one shot or short story for her and her brother, who will be described below)  

  
Name: Benjamin Marshall
Age: 7
Eye color: Blue
Hair color: Dark brown
Likes: Batman, his stuffed deer, stories, games, and nature.
Dislikes: The Joker, bullies, the color orange (don't ask why), etc.
Family: His sister (Rosalina) and stuffed deer (Clover).
Location: Gotham city orphanage