Darkness - Farren

Farren, a young girl of fifteen, runs away from home, to escape being institutionalized only to be taken hostage. She was saved by a person she would come to think of as her mentor, best friend, but most of all her father. Bobby Singer.

Upon saving a young runaway, Bobby realizes what the future will hold of someone like her. He take her in and raises her in the ways of hunting, teaching her how to defend herself and keeps her safe, sheltering her from the world as much as he can, for as long as he can.

That all ends when the Leviathan become part of the game. And she meets the Winchesters.

Farren unwittingly places herself in the middle of the Winchesters war. In so getting into trouble of her own and falling in love.