I think this was the site linked previously:
VSED Resources Northwest.
This sounds like the lady you're thinking about; family made a documentary:
Rosemary Bowen's Fast
At age 94, Rosemary Bowen hastened her death by voluntarily stopping eating and drinking (VSED) in 2018. For twenty years, Rosemary Bowen had told her family that she would hasten her death when she was no longer able to live independently. Several months after suffering a back injury, she decided that she was ready to die. Rosemary asked her daughter to make this video to show others that VSED could be a sensible end-of-life option.
IMO it's good to have this information and these advocates out there, but it sucks that the laws don't allow the choice of medical aid in dying for people with a dementia diagnosis. It seems like it's mostly people consciously facing dementia, with some older people who see VSED as "suicide lite;" they wouldn't kill themselves and probably wouldn't go for MAID, but just stopping eating is acceptable to their morals.
(It's interesting that an end-stage dementia patient (or other terminal illness) do slowly drift away from eating and drinking at the end. Someone who's 83 and cognitive but also just kinda tired and done with living now; is that VSED when they stop eating? Or is that just the same instinct as the terminal cancer patient, it's just that there's no one single cause to point at? The whole thing is sad and fascinating and I wish we did better by our elders.)