Shelly, 40, was killed in November, allegedly by a workman renovating a Greenwich Village apartment one floor below her office, People magazine said. Shelly reportedly confronted the worker earlier about noise.
After the weekend Sundance premiere of "Waitress," Russell told People, "I haven't ever been part of a film that has so much good will here."
Shelly completed "Waitress" -- a "dramedy" about a pie-baking waitress who finds herself pregnant -- before her death. Although it had been accepted at Sundance, she hadn't been notified.
"There's a joie de vivre in this film that I think Adrienne would want us all to celebrate," festival director Geoffrey Gilmore said when introducing the film.
Russell said the film was "refreshing" for the crowd.
"I just can't believe (Shelly) isn't here to experience this," she said.
Shelly's husband, Andrew Ostroy, announced the creation of the Adrienne Shelly Foundation, which will give scholarships and grants to female filmmakers.