James Wightman married about 1768, Mary Davis, born 17 July 1749 in Exeter, Rhode Island; died 10 November 1832 in East Greenwich, Rhode Island, daughter of William and Elizabeth (Gifford) Davis.
Mary (Davis) was a younger half-sister of Martha (Waite), wife of his brother John, Martha being the eldest child of their mother's first marriage to Joseph Waite of Exeter (died in 1744, age twenty-six).
Whitman, Mary Ross. George Wightman of Quidnessett, R.I. (1632-1721/2) and descendants : Waitman, Weightman, Whiteman, Whitman, Whytman, Wightman, Wyghtman. Chicago, Ill. 1939. Page 78.
It may be possible to confirm family relationships with Mary 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 Mary: