Their Eyes Were Watching God might in some sense be considered a combination of those two books: it's a (girl's) coming-of-age story and also rather dramatic a la The Great Gatsby. And it's just awesome in general; more people should read it.

All Quiet on the Western Front could also appeal to her. As with Catcher in the Rye and Great Gatsby, it explores the disconnect between social niceties and what lies beneath them.