Billie Letts, the mother of the Chicago playwright Tracy Letts, recently died in her home state of Oklahoma, The Chicago Tribune reported.

Billie, who was 76, was a highly regarded novelist (as well as a teacher and screenplay writer) whose works include Where the Heart Is, which sold more than 3 million copies and was turned into a movie starring Natalie Portman.

She was married to the actor Dennis Letts, who died in 2008, shortly after appearing in his son Tracy’s Pulitzer Prize-winning play August: Osage County, initially at Chicago’s Steppenwolf Theatre Company and then on Broadway.