Ruby (1977)

Ruby is a 1977 horror film directed by Curtis Harrington and starring Piper Laurie.

Plot
In 1935 Florida, a lowlife mobster, Nicky Rocco, is betrayed and executed in the swampy backwoods as his pregnant gun moll, Ruby Claire, watches. He swears vengeance with his dying breath, and then she suddenly goes into labor. Sixteen years later in 1951, Ruby is now running a drive-in theater in the backwoods near her home and employs ex-mobsters to run the theater. Her 16-year-old daughter, Leslie Claire, is mute and has been since birth, and resides in the home with Ruby, her lover and henchman Vince, and Jake Miller, a blind, wheelchair-bound former mobster who had his eyes cut out. Ruby spends her days overseeing the theater's operations, as well as lamenting her short-lived career as a lounge singer.

Trivia
The film is a fine example of a The Exorcist rip-off, with a similar plot about a woman's mute daughter being possessed by the evil spirit of a deceased lover, who died the night she gave birth. Her co-workers at a drive-in are also killed in gruesome ways.