Joan Fontaine with Gary Cooper the year they won Oscars for “Suspicion” and “Sergeant York” respectively. From the Los Angeles Times photographic archive, UCLA Library.

Joan Fontaine died Sunday at her California home at age 96. The actress was famous for playing seemingly mousy women with hidden reserves of steel (“Suspicion,” “Jane Eyre”). She was also well-known for a feud with her older sister, Olivia de Haviland, that apparently turned on Olivia losing out to Joan for the Oscar the year Joan won for “Suspicion,” even though Olivia would win twice for “To Each His Own” and “The Heiress.”

I can’t imagine that was the only thing on which the rivalry turned. Sibling relationships and rivalries are complex. And when the rivals are women, well, the games they play are more subtle than those of men but no less painful. Who snubbed whom at a party, who neglected to send a birthday card: It’s all so passive-aggressive, death by a thousand spoons.

Joan Fontaine always said that if she died before her sister, her sib would be livid. Well, she’s trumped her again.

You have to wonder, though, if Fontaine rued their difficult relationship and if de Haviland rues it now.

Perhaps not. And that’s the hell of it.