I am one of Mary Catherine's great-granddaughters. My grandmother was Emma York-Daves wife of William S. Daves. My mother was Betty K. Gray-Butler and I am Jewel Orvilla Butler-Gibson.
Was you Great-grandfather John York? If so, you will find his dad listed as Melvin L. York and his wife Narcissus in the Palo Pinto, Tx census.
In 1900 Mary had already married Wm. S. Daves in 1889 and was living in Dallas, Tx. Mary died Jan 23, 1932. She is buried in the Brazos, Palo Pinto County area. I think she IS buried next to William with no marker. Please feel free to contact me at firstname.lastname@example.org