As a 12 year old I thought this book was great I read this book atleast a year ago and I still remember the whole story!!!!!This novel deosn't really have dolphins it's just that the island has alot of dolphins around it so that's how it got it's name. But there are some part's with dolphins and there are these wild dogs in the story as well. They help her in parts and it's just a lovely book. you must read it. I'm sure you'll enjoy it. I say it's for ages 9 and above but if there sre some good readers that are younger they should read it too.