Bestselling author of Pretty Little Liars and The Lying Game series. She is well-known for her works of young adult fiction. She has also published a handful of novels for adults, including The Visibles (2009) and Everything We Ever Wanted (2011).
She attended New York University and Brooklyn College. She published her first novel, Pretty Little Liars, in 2006.
She appeared in a cameo role in a Season One episode of Pretty Little Liars, the ABC Family show based on her series of novels. In 2021, she wrote a book with Lilia Buckingham called Influence.
She was born to a Canadian mother and an American father. She grew up in Downingtown, Pennsylvania.
Pretty Little Liars, the TV series based on her books, starred actress Lucy Hale.