What is the author's style in The Second Summer of the Sisterhood by Ann Brashares?

The Second Summer of the Sisterhood is written from the perspective of a third-person narrator. The narrator is omniscient, providing the reader with not only factual information, but also the inner thoughts and feelings of the various characters. The book contains an appropriate balance of descriptive exposition and dialogue, and is also sprinkled here and there with portions of letters, notes, e-mails and instant messages that are exchanged between various characters. The book focuses entirely on Lena, Carmen, Bridget and Tibby, giving little or no insights into the thoughts of the novel's other characters.

The exception is the book's brief prologue, which is narrated by Lena. This portion of the novel serves as an introduction to the story, providing a short history of the relationship among the four main characters and a description of the traveling pants and thier importance in the girls' lives.