Dreamland by Alyson Noel (author) (UK edition)

“All I wanted, all I’d ever dreamed of, was to be thirteen. But then I died.

Riley Bloom’s afterlife is about as good as it gets, except that she’ll never be a teenager. Riley desperately wants speak to her older sister, Ever, and ask for her advice. But Ever is still alive, and the only way Riley can reach her is to search for Dreamland – a place where ghosts can jump into dreams and talk to their loved ones. Only when she finally gets there, Riley discovers that Dreamland isn’t as heavenly as it sounds. In fact, it’s a total nightmare…