The Girl Who Wasn't There - Jacqueline Wilson

A spine-tingling, mystery tale for 9-12 year old readers from the bestselling Jacqueline Wilson.
'And we're going to live here, happily ever after, just like a fairy tale.'
When Dad tells Luna and her little sister Aurora that they're moving to live in a real tower, it's almost like they've stepped inside a fairytale.
But everything is not as magical as it first seems. The tower needs patching up, Dad still doesn't have a job and they're not even allowed in the room up at the very top.
When it's time to start at their new school, Luna quickly finds a friend, but six-year-old Aurora absolutely hates the children in her class. She prefers to spend her time with her imaginary friend Tansy. Aurora's make-belief life causes problems for them all - and it seems like Aurora really believes Tansy exists...
Is there really a curse on the tower - and will Luna be able to break it?