The lonely agent

Hey,
thank you so much for reading my book.
I hope you'll support me by telling me if I can do something to make the story better to read for you. I am not English, so I will make some mistakes sometimes, but please bare with me. I'll try my best to make my book to the best of my extend.
xx Helena

The story is about special agent Katherine Pierce, who is still in high school. She is 17 years old, and angry. Her parents died in a car accident when she and her twin brother Kai Pierce where only 6 years old. Katherine was also in the car, but she lost conscious once they hit the water. Her parents drowned, but somehow she got out of the car and ended up in a forest 10 kilometers further. When Katherine and Kai turned 15 something happened, but they decided to never speak of that again. Whatever did happen ended up in getting both Katherine and Kai in the special forces of the English army. Katherine soon became the leader of the group, meaning she finally had the resources and the authority to find out who killed her parents. And she is going to use that...
You'll be reading the book out of Katherine's point of view.