Likely from Alzheimer's which she had been battling the last five years (eerie parallel to her character from The Notebook).

https://tvline.com/news/gena-rowlands-dead-peyton-place-emmy-winner-obituary-1235319337/

Thats sad........ I love Gloria (1980)

Another great actor gone to rest from our Modern Times...The Notebook was a favorite.

I havent seen that one.........