I see on Facebook that Grace Griffith has died after suffering from Parkinson's Disease since the 1990s. She was well-known in the folk community in Washington, DC. She die on June 5, 2021. She was 64.
May she rest in peace.

https://en.wikipedia.org/wiki/Grace_Griffith

https://gracegriffith.com/

Here's her YouTube channel, which has lots of examples of her beautiful singing:

https://www.youtube.com/channel/UC-Lju4UICiPXXe-EJDky3fw

I highly recommend that you take a listen to this remarkable singer.