24 is a 17 year old orphan. She was raised in an orphanage and never got adopted, rather, she was kicked out on her 17th birthday. 24's real name is Anastasia, but after her mother was murdered she was sent to an orphanage and was rather referred to as 24. She is the main character of a novel Prez wrote, In the Dark of the Night.
24's father, Royce Thompson, and older brother, Emmet Thompson, had been murdered before she was born, and her mother, Princesss Syria Smith-Thompson, had barely managed to escape. She was born as Princess Antasia Marie Thompson about five months later, on June 10th, 1995.
Despite only having one parent and being on a mass murderer's hit list before she was even born, Anastasia's early childhood had been essencially perfect. She lived in a big house with good friends and a mother that loved her, and what else would she ever need?
Anastasia's life was going perfectly and happily up until her 7th birthday.
Anastasia was playing with her closest friend, Gregory Hampton, in her front yard when she saw her pregnant mother Syria running from something. She yelled at Anastasia and Gregory to get inside, which they did, alarmed because Syria had never raised her voice near them before.
Finally, a dark figure followed Syria to the road and caught up with her. He had another dark figure hold Syria's arms behind her back, and as the children watched he brutally murdered the 25-year-old Syria (happy birthday, Anastasia!). Greg called 911 as Anastasia simply stood there, speechless, staring at her dying now-armless mother, in a shock.
Syria died and the criminal went uncaught. Anastasia was sent to the orphanage.
Because of her past and her being a princess (though she did not know this at the time), she was treated quite nicely by the teachers at the orphanage. However, the children bullied her. For a year after her mother's death, she was angry and withdrawn. For a year after that she cried a lot and was mostly depressed. Finally, she just shut down her emotions altogether. She basically became a robot, the only evidence she has a soul being when she gets mad, on her birthday (when she gets depressed), and the locket she wears around her neck which has a picture of her mother, her father, and Emmet in it.
Nobody at the orphanage could remember her name, so she was simply called 24. Eventually, not even she could remember her name. As such, she was no longer Anastasia, but 24.
By the time she was 16, she could no longer remember most of her perfect childhood. Only her 7th birthday, afterwards, and bits and pieces of before that. She could remember Greg faintly, and through her flashbacks, fell in love with him.
On her 17th birthday, she was kicked out of the orphanage and she's currently searching for Gregory.