I am uncertain that any Demasters family researcher has ever conclusively proven that today's more-or-less accepted spelling is correct. Some with whom I I have exchanged information tell me that the name can be found a Demastus, Damastas, etc. I use the spelling that I have most often found; e.g., Demasters.
Mary "Molly" Demasters was born Dec. 4, 1804 (no source) and died before 1860 (no source). She married William Benjamin Coffey on Nov. 13, 1824¹ in Nelson Co., VA, was living in that county at the 1850 census and was a widow there in 1860. She died Apr. 22, 1867 but, her place of burial is not known to me. She was the daughter of John and Martha "Patsy" Moran Demasters. According to a typewritten letter dated Oct. 10, 1934 to Mrs. Leo W. Kasehagen of Washington, D.C., (sender not identified), this couple was married on Jul. 29, 1779 in Lyndhurst, Augusta Co., VA.²
William Benjamin Coffey was born c1805, probably in Nelson Co., VA, to Edmund F. and Elizabeth Burger Coffey. He died on Apr. 22, 1867³ in that county. His burial site is also unknown to me.
To the union was born at least seven children: Morris W.; Martha Ann; Edmund Franklin; Egbert; Nancy; Elizabeth and William Benjamin, Jr.
1) Morris was born Aug. 12, 1825 in Nelson Co. His wife was a double third cousin, Mildred Annister "Milly" Coffey, a daughter of John W. and Margaret Susanna "Susan" Coffey Coffey. John W. was a son of Edmind Steward Coffey, Jr. and his wife Matilda "Tildy" Fitzgerald. Susan's parents were Reuben G. and Nancy Giles Coffey.
Children born to Morris and Milly were Mary Ann Elizabeth (1860-1946), who married Joseph Clay Hewitt (1847-1920). Second was Nicholas Anderson "Nick" (1861-1956) who married his several times cousin, Viola M. A. Coffey, a daughter of George Washington and Rachel A. Campbell Coffey. Next was John Walton Coffey (1866-1945) who also married his several times cousin, Sarah Henry "Sallie" Coffey, a daughter of the George Washington Coffey who married Mary Catherine "Kitty" Demasters. Kitty was a daughter of John and Mary Ann "Polly" Coffey Demasters. Following John Walton was Alice Sophronia "Allie" Coffey (1870-1955). Her husband was Hugh "Hughey" Coffey (c1861-?), a brother to Sarah Henry Coffey.
2) Martha Ann "Patsy" was born c1827 in Nelson Co. Nothing more is know.
3) Edmond Franklin (1829-1906) married twice. His first wife was Mary Jane Camden (c1829-?). Their children were Lucas T. (c1859-?); William Luther (1861-1890) and B. E., a son, born 1866. This son married I. B Jackson on Fb. 3, 1892 in Wythe Co., VA.# His second wife was Sarah Margaret Smith (c1841-?) to whom he was married on Nov. 18, 1867 in Nelson Co.± Their children were Hugh (1869-1870); Mary Jane (c1871-?); Nora Kate (c1872-1940); Elizabeth Dora "Betty" (1873-1954), married Edell Alexander Brown (1870-1933); Cofa Lee (1875-1875); Florence Pearl (1875-1960) and Julie Ann (c1878-?)
4) Egbert, 1831-?) married Martha Monroe on Fe. 23, 1854 in Nelson Co.* Egbert was a volunteer with Co. E., 51st Inf Regt., CSA, Nelson Co. I know of only one child, as son George W., born 1855.
5) Nancy (c1831-?) married Peter S. Fitzgerald on Jan. 18, 1848 in Nelson Co.** Peter and Nancy had at least three children: James W. (1851-?); Sarah Elizabeth, (1850-?) and Napoleon D., (c1866-?). James married Mary S. Coffey, a daughter of William W. and Sarah Jane Coffey Coffey. William W. was a son of William who married Elizabeth Giles and Sarah was a daughter of his brother, Reuben G. Coffey who married Elizabeth's sister, Nancy Giles. Sarah Elizabeth married Lorenzo D. Fitzgerald, a son of Moses W. and Mary Ann Coffey Fitzgerald. I suspect Lorenzo and Sarah Elizabeth were cousins but I cannot find the parents of his mother, Mary Ann Coffey Fitzgerald. Napoleon married Martha Elizabeth Coffey, a daughter of William David "Billy" Coffey and wife Samantha Elizabeth Campbell.
Nothing more is know of child 6) Elizabeth and child 7) William Benjamin, Jr.
Many of these families have descendants. Information on individuals is available. The entire family, including sources, is included on the Edward Coffey Project DVD.
¹Marriage Register, Nelson Co., VA, Part 2, Page 19, Line 20. This marriage register names the groom as William B. Coffey and the bride as Mary F. Masters with E.F. Coffey and John Masters as security.
²Coffey Cousins' Clearinghouse Newsletter (Jefferson City, MO: Bonnie Culley, March 1996. Winifred, dau. of John and Jane (Jean) Graves Coffee. One of their children, Martha "Patsy" Moran m. John DeMasters. John served in Rev. War and Martha drew a pension on his war record. See Issue 62, page 9 at http://tinyurl.com/qbfdt2c
³Nelson Co., VA Death Register, Page 22, line 5
#"Virginia Marriages, 1785-1940", index, FamilySearch (https://familysearch.org/pal:/MM9.1.1/XRSH-G13 : accessed 25 Feb 2013), B. E. Coffy and I. B. Jackson, 03 Feb 1892; citing reference Page 8-5, FHL microfilm 34255. This child has not been found in the census record with the Edmund F. Coffey who married Mary Jane Camden.
±"Virginia Marriages, 1785-1940", index, FamilySearch (https://familysearch.org/pal:/MM9.1.1/XRZR-CQS : accessed 25 Feb 2013), E. F. Coffey and Sarah M. Smith, 18 Nov 1867; citing reference p 20 ln 54, FHL microfilm 32734.
*Marriage Register, Nelson Co., VA, Part 2, Page 63, Line 11.
**"Virginia Marriages, 1785-1940", index, FamilySearch (https://familysearch.org/pal:/MM9.1.1/XRZT-QPX : accessed 09 Mar 2013), Peter Fitzgerald and Nancy Coffey, 18 Jan 1848.