Dualed by Elsie Chapman

In this book there is a girl named West. West lives in an era where no one can give birth to children so they have to go to labs to have children made. When they make the kids there are 2 copies. Later in the your life before you become 20 you have to battle your copy so that only the best one lives. In the book West is activated and she and her copy have 1 month to kill each other. This book is sort of violent, less than you might think. Despite how violent it is I think its good.