Shelly's "Waitress" was one of the 123 films picked to screen at the Utah film festival in January -- a development that those involved with the film say is bittersweet, the New York Post said.
The actress was killed in her apartment Nov. 1.
"I wish Adrienne was here to enjoy the success of the film. She worked so hard and she is the film, really," said Cheryl Hines, one of the film's stars.
The 40-year-old actress-director's death had originally been thought to be a suicide, but was later ruled the result of a heated argument with construction worker Diego Pillco, who has confessed to the killing, the newspaper said.
"Waitress" was selected for Sundance from among more than 3,000 films submitted to the festival.