|Green Mansions (1959) [Rima]: Possibly burned to death when a group of natives (led by Henry Silva) set fire to the tree that she had climbed. She appears at the end of the movie after Anthony Perkins remembers her telling him the legend of a flower that never dies; her appearance could be interpreted either as showing that she survived, or that she is a vision or spirit. (Thanks to Jack)
Robin and Marian (1976) [Maid Marian]: Commits suicide by drinking poison, after giving the same poison to Sean Connery. She is shown slumped against the wall and growing steadily weaker; the movie ends before she actually dies.
Always (1989) [Hap]: Dies (off-screen) under unspecified circumstances, some time before the story begins; she appears as an angel assisting Richard Dreyfuss throughout the movie. (Thanks to Tommy)