There is documentary proof that Peter Davis was the blood grandfather of Berryman Green, Thomas and Lucy's oldest son. Even the family history written in 1915 by Emma Green Phillips, Berryman's great grand daughter gives Lucy Davis Green as Berryman's mother. Berryman Green was born on 31 Jan 1753, probably in Amelia Co VA, as Peter Davis bought land there in 1742 and moved his family there from Goochland Co. VA.
It may be possible to confirm family relationships with Lucy by comparing test results with other carriers of her mitochondrial DNA.
However, there are no known mtDNA test-takers in her direct maternal line.
It is likely that these autosomal DNA test-takers will share DNA with Lucy: