I think this is the exposition as it is the start of something terrifying for Janie. It is the scene where she finds her face on the milk carton, and the scene where her life turns upside down.
I consider this scene to be an inflicting action as Janie starts to get daymares of her old childhood and her real family. She refuses to believe she truly is kidnapped, but can't hide from the truth.
This scene is also a rising action as Janie is determined to find information her "parents" are hiding from her. She goes up to the attic, and instead of finding information about her, she finds old schoolwork and photos of a girl named, Hannah.
I think this scene is the climax as Janie's "parents" tell her the truth. They tell her Hannah is their daughter and Janie's mother. She supposedly gave Janie to them in hope of a better childhood. Janie questions why it shows she is kidnapped and begins to think if that story is fake.
This scene is the falling action as Janie comes to the conclusion that Hannah is the one who kidnapped her, and her "parents" never knew the true story either. She convinces her boyfriend, Reeve, to drive to her real parents house and get a glimpse of her true life.
This is the resolution and end of the story. Janie's "parents" know that the best thing to do is contact her parents and let them know that she is okay. Janie doesn't want her life to change, and is afriad of what's to come.