It was previously unknown how the lady of Woodstone Mansion died in Ghosts, but Hetty Woodstone revealed her cause of death near the end of season 3. Rebecca Wisocky portrays a high-status spirit, a former robber baron, and a distant ancestor of Rose McIver’s Sam character. As the only ghost who inhabited and owned Woodstone Mansion while living, Hetty acts like she has it all together. Still, season 3 forced Hetty to reveal her dark past to her cohort of paranormal friends. As such, Hetty’s death explains one of the last unknown pieces of the ghosts’ backstories.

https://screenrant.com/ghosts-hetty-death-meaning-explained/