Peterfreund's first book, Secret Society Girl, is about a college student who gets tapped for a secret society. The school in the novel is based on her time at Yale. The New York Observer described the book as "witty and endearing", and Booklist described the book as "frivolous but fun to read", Three other books were released in the series.
In 2009, Peterfreund released Rampant, a young adult novel about a girl who hunts unicorns. Publishers Weekly wrote that the book was a "gripping page-turner".
She has also contributed to several collections of essays.