Lucinda Stanley was listed on the 1900 Dickenson Co, VA census in HH #346. She was the Head of the household and no one lived with her. Her month and year of birth are listed as unknown, age 55, mother of 2 living children; she b. Va; her father b. NC and mother b. VA.
The above age for her appears to be incorrect as on 1850 Russell Co, VA Annotated Census her age is given as 18. Detailed info with source: 1850 Russell Co, VA Annotated Census:
HH# 1524 Stanley Larkin, 21, Russ.(s/John Stanley & Ollie Baker )- Src., Susan Jurban, firstname.lastname@example.org
HH# 1524 Stanley,Lucinda LONG,18,Grayson (d/Samuel Long & Mary Schunte - Src., LDS Ancestral File)
On censuses for 1860, 70 & 80 her age was given differently each year, which is normal for some.
Sorry but I have no idea when she died or where she's buried.
Do hope this helps in some small way.