I was an ardent reader of Sweet Valley for several years, and my interest waned until I read this and its companion book. It was a great way to get my interest back in time for the new Sweet Valley Jr. High and Sweet Valley Senior Year (which I read at the same time, since I felt Jr. High was a bit too juvenile and more of a guilty pleasure).
In this book, Jessica acts a lot more like Elizabeth than herself when she goes to Hawaii with the Unicorns and feels like an outcast.