Autumn Francia Because no magic or other paranormal events take place in this book and it could actually happen to someone, even if the events that created it in this may seem unlikely, they are entirely and highly possible. There is nothing like a 'Talking Car' or a 'Flying Carpet'. This is realistic fiction because it is almost hard to tell if it is based off of a true story or not.
This answer contains spoilers… (view spoiler)[This book is realistic fiction because cults are a lot more common than people think. If Hannah was a real person, she would be utterly terrified to leave the cult in fear of them tracking her down and bringing her back or worse. Also she could have feared her parents not letting her come back home and being alone, therefore taking Jennie/Janie incase she was rejected once home. Definitely plausible, just not likely to happen. Today you see ads for kids who were kidnapped in the 80's missing still, it's definitely possible for a girl to find her ad twenty years later, let alone twelve. (hide spoiler)]