Backstory: Emma Stones was born in New York a 15 of July. His mother disappeared when she was only one year. The only thing that she have of her is an anklet that, according to what her father said, he would protect her. When she was five, her father marry with other woman that have a daughter. Her stepmother did not treat her well: when her father left, she called him a "freak" and sometimes even inflicted physical and mental harm on her. In the school, older boys bullied her. But her father, Charles, found out. When she was ten, he realized that his wife hurt his daughter, and he got divorced. This act gave her the courage to confront the bullies at his school, who left him alone. That year was the best of the Emma's life: She went to school and saw her father after that. She slept well, not than other years. But the happiness don't last more. One day who was not wearing the anklet, after school, she saw her father in the floor, dead. Next to him was a man. He saw Emma and go next to her. She ran. In a street, other men prevented her from passing. Behind her was the other men. They caused her many injuries, such as one on her right forearm, another on her eyelid or another on her left leg. But the worst of all was what they did to the heart area, since it was very deep. In some strange way, she arrived at Camp Half-Blood, and she fainted on top of another camper. Days later, she woke up. Emma didn't know where she was, but she knew she was alive. Time after, she knew that she is a demigod, daughter of Athenea, and that the Camp Half-Blood was her place.
Thanks to @cosasdeiria for showing me the world of Percy Jackson and to @Tuquoise_Lake77 for insisting on taking it from the library.