|Chinatown (1974) [Ida Sessions]: Murdered off-screen (exact method unclear) by thugs; her body is shown afterwards when Jack Nicholson finds her lying on her kitchen floor.
Embryo (1976) [Martha]: Poisoned (off-screen) by Barbara Carrera to induce a heart attack; her body is shown afterwards in the morgue when her brother (Rock Hudson) identifies her.
Rambling Rose (1991) [Mother]: Dies (off-screen) of unspecified natural causes, at some point between the main portion of the movie and the framing sequence.
Forever (1992) [Mabel Normand]: Dies of tuberculosis (off-screen), many years before the story begins; she appears as a ghost (appearing as she did in the heyday of her screen career) throughout the movie.
Carnosaur (1993) [Dr. Jane Tiptree]: Dies (off-screen) while giving birth to a dinosaur. (Thanks to PortsGuy)
Dr. Quinn, Medicine Woman (1993 pilot movie) [Charlotte]: Bitten (off-screen) by a rattlesnake; she dies shortly afterwards with Jane Seymour at her bedside. (She occasionally reappeared in flashback sequences in later episodes of the series.) (Thanks to PortsGuy)
Hush Little Baby (Mother of Pearl) (1993) [Edie]: Falls out of a window. (Thanks to PortsGuy)