Billie Letts
Credit: Renee W. Nicolo/AP

Billie Letts, the author of the bestselling novel Where the Heart Is, has died. She was 76, and according to her son Tracy Letts, she died of pneumonia.

Letts taught at Southeastern Oklahoma State University and published her first book, Where the Heart Is, about a pregnant teenager abandoned by her boyfriend and stranded in a WalMart, in 1995. When the book was released in paperback, it caught the eye of Oprah Winfrey, who featured the novel on her television show.

Winfrey’s endorsement shot the book up bestseller lists. The novel has sold more than 3 million copies worldwide, according to The New York Times. In 2000, a film adaptation of the book was released, starring Natalie Portman and Ashley Judd. Dennis Letts, Billie’s husband, and also had a role in the movie—he became an actor once he retired from teaching.

After publishing Where the Heart Is, Letts wrote three more novels—The Honk and Holler Opening Soon, Made in the U.S.A., and Shoot the Moon.

She is survived by three children: Dana Letts, Shawn Letts, and playwright Tracy Letts. Tracy won the Pulitzer Prize for Drama for August: Osage County, which was adapted into a 2013 movie starring Meryl Streep.