When I ordered this book we had our son who was four years old and had recently had my daughter. My son LOVES books and he was ecstatic to have a book where he and his little sister were the main characters. This book has helped him see that they are a team and can work together. I could see that this would have been hard for him to understand at the time where he was already so capable and having a little sister who did barely more than a lizard at the time. As they grow older we will be reading both of them this book. It will be magical to watch their eyes light up.