Cecilia Burke was the daughter of a soldier. When her father died in combat, her mother to suicide, she was sent to live in foster homes. After a long succession of terrible foster homes--where she was abused and neglected--she aged out of the foster care system and ended up on the streets. For a few years she wandered, lost and alone, until a mysterious yet kind stranger took her under his wing. He taught her many useful things: how to kill in many different ways; how to disappear in a crowd; how to infiltrate almost any building or group or stronghold; how to move unseen in the shadows; how to use myriad different weapons...
For a time she worked for this man, whom she called Mister X, as an assassin-for-hire. Her one code? She refused to kill children. To this end, Ceci--or Celenophia as she came to be called in hushed whispers--would outright blacklist anyone requesting such and would sometimes even pursue the person themselves who had attempted such a heinous thing, to hire an assassin to kill a child.
She lived in this manner quite comfortably, travelling the world, integrating into many different societies, equally at home pretending to be a rich heiress or socialite or a poverty-stricken beggar on the streets. She could play every role needed to acquire a clear shot at her intended target; rarely did she miss or fail to achieve her goal.
When she was twenty-six she was hired to assassinate a high-ranking diplomat. The country where this diplomat was stationed did not matter to her, only that the woman had to die. She stalked her target, learned the ins and outs of the woman's daily life, the habits she followed without fail and without realisation. For weeks, then well over a month, she studied her target, watched her take her children to school, pick them up, go to work, return home to cook and clean, watched her live her normal life. Then the day came when Ceci felt it was right to strike.
The rifle was heavy in her hand as she set herself up 480 meters away from her target. She got into a comfortable position in the eves of the bell tower she'd hidden herself within. The scope on her rifle remained closed, but she watched on occasion with a rangefinder, waiting for zero hour, when a single bullet would end the life of a woman who stood in the way of Ceci's employers, and thusly her getting paid.
The driver pulled in front of the woman's home, opened the rear door in preparation to take her to work. Ceci flipped up the cover on the scope, set the range to 500 meters, took aim...and as the woman exited her home she gently squeezed the trigger. The shot was loud within the bell tower's confined space, but she had ear protection. It didn't matter if the shot were silent or not. She was covered from head-to-toe, would leave no trace behind, no clue from with authorities could pull DNA, no prints. Nothing. She watched through the scope as an explosion of red flecked back into the brick, the doorway, saw the woman turn from the punch of the bullet, watched her fall in horror...and saw to her growing horror the baby on her back had been nearly obliterated. It was clearly dead...from the plethora of pink, a girl.
The diplomat herself lived, but her infant daughter--whom Cecilia had not known would be there and had not realised was bundled onto her mother's back--died immediately. Full of remorse, Cecilia gave up being an assassin and began to wander the world, taking the occasional job as a bounty hunter but never again able to pull the trigger and take a life.
Until the outbreak. She was in Russia at the time, and as the infection spread, the plague that robbed people of thought and reason, that turned them into mindless creatures which attacked everyone they saw or heard, she passed further into Russia, and then into Chernarus unknowingly, slipping through the border over the mountains and with great difficulty. It was simply another place to go, but once there she found herself trapped. Firstly by water and secondly by a completely closed border. Forced to remain in Chernarus, and with the epidemic having reached epic proportions, Cecilia finally choose to take up arms again, this time solely to survive.