In the Snopes investigation of the story, the fact-checkers note that no contemporaneous documentation of the events has been found, and they assess the claim as “unproven” — a rating that acknowledges the lack of corroborating evidence while declining to definitively label the story as false.

This is the appropriate epistemic position: the story cannot be verified, but it also cannot be conclusively disproved.

If the sister exists and arrived late and requested the opening of the grave, she would be one of the most remarkable figures in the story — the person whose grief and determination, or perhaps simply whose tardiness, accidentally saved a life.

But she remains nameless and unverified.

Living With a Legend