Grey to Green: Gin's Sister (A Detective Conan Fanfiction)

Neliel Edenburg is the name that was given to her so many years ago, and the name she's gone by for so long now. Neliel, better known as Nel or Nellie, is a member of the Black Organization. At fourteen years of age, she is the youngest member, and the organization's finest assassin.
She is also Gin's younger sister.
Born on a snowy winter night in Moscow, Russia, she and Gin fled from their abusive parents to Japan, hoping to start new lives. However, thanks to a certain incident, the two of them found themselves deeply entangled within the Black Organization. As a result, Gin rose through the ranks as the years passed, and Nel was trained to become an assassin.
Then things took a turn for the worst. Considered unstable, a death order is given to kill Nel, and left without a choice, she escapes. During her escape, she hits her head and scrambles her memories, and winds up in a daze on Professor Agasa's front doorstep.
And just when Nel is finally about regain her memories, the Black Organization sends agents to kill her after her betrayal of the organization. They're furious, and determined to kill her no matter what, even going as far as pitting elder brother against younger sister.
Can Nel free herself from the clutches of the Black Organization once and for all? Can she regain her freedom? Or is she doomed to die at the hands of none other than her older brother, Gin?