I'm Not Real?

A 14 year old girl, Em (Emily), had a great life. She was happy. Had an amazing family. Yes she had challenges but everyone does. Read this story to hear about her growing up. Three months after she turned 14, she got in a car crash and passed away. Then she woke up, but not as herself...

Cassie, the same age as Em, woke up. Where am I? Why am I here? Her mom walks in.
"Hi honey how was your nap?"
"Who are you? The better question, who am I?"
"Cassie stop playing games"

Why did she have this dream? Why was it so real? Read to find out! Enjoy:)