Saving Neverland by Abi Elphinstone

Martha Pennydrop is ten, and desperate to grow up. But growing up is a tricky business. It means turning your back on imagination, fun and magic, because those were the things that led to the Terrible Day when something awful nearly happened to Martha’s younger brother, Scruff, which would have been all her fault. But when Martha and Scruff discover a drawer full of mysterious gold dust in the bedroom of their new house – along with a window that’s seemingly impossible to close – it’s the start of an incredible adventure to a magical world: Neverland!