Escape Notes

Two sisters (?) living with their grandfather (?)
Older sister (18?) is very mature, calm
Younger sister (12?) is nervous, excitable, and simple-minded
Older sister moves out to marry a wealthy man
Younger sister left alone with grandfather
Grandfather begins to sour as he becomes obsessed with money
Abuses younger sister and forces her to work
After a year or so, she plans to escape
Tries to escape through the window when her grandfather discovers her
He tries to attack her with knives, and she manages to fight back
Receives several stab wounds before she gets him off and jumps out the window
Struggles to leap fence and escape to the parking lot, where she encounters a group of people
They're there to help her escape, and take her in their van
Ends as she asks for medical help

Young girl is implied to possess some sort of strange ability or power that has been untapped
"Rescue" group is implied to be in association with her older sister
Might be some sort of secret refuge for gifted youth?