This is the only Deb Caletti book I have ever read, but since reading it I have recommended her books to teens several times. The Fortunes of Indigo Skye is the story of a normal girl who has something rather extraordinary happen to her. Indigo is finishing her senior year of high school and working as a waitress when she meets "Vespa guy". He comes into the restaurant simply to order a cup of coffee in the morning. It's not until Indigo scolds him for smoking (a pet peeve of hers) that he comes out of his shell to talk to her. Later that day he leaves her a letter, within which is a check for 2.5 million dollars.
From here the story becomes fairly typical, mostly what you would expect from a story where a teen all of a sudden comes into a bunch of money. Indigo has to learn how to keep her promise to Vespa guy, who asked her to use the money to make herself bigger, rather than smaller. She fails rather miserably at this task initially, buying all sorts of things she has no need, or even any real desire for. Her money changes her relationships with her friends, family, coworkers, even her boyfriend. Indigo does learn her lesson, and although the story is a little bit predictable, Caletti's characters have enough depth to make up for it. The characters themselves are not cardboard cutouts of each other, or of some archetype or another. They are solid, well drawn individuals, and this is what truly makes the story.
Like I said, I have not read any of Caletti's other books, but if they are anything like The Fortunes of Indigo Skye, they are well worth recommending to any teen, especially girls looking for something a little bit different.