*Fannie Frye
born 1804 Virginia
died between 12 February 1836 and 10 June 1838

father:
*John Frye
born 2 April 1774
died 28 October 1826

mother:
*Mary Collins
born 1 December 1770
died 15 June 1861
married 1795/96 Frederick, Virginia

sibling:
Eliza Frye born 1817 Virginia
Henry Ferguson Frye born 2 April 1803 died 2 January 1887
Sarah Frye
Mary Frye
Rhoda Frye
Celia Frye
Amanda Frye
Rebecca Frye
Noah Frye

spouse:
*Thomas Mercer
born May 31,1800 Chester County, Pennsylvania
(1840, 1850, 1880 census says born Virginia)
died 14 March 1879 Pike County, Benton Township, Ohio
married 1825

children:
Rebecca Mercer
Joseph Mercer
William Mercer
*Thomas Jefferson Mercer born 12 February 1836, Calais?, Somerset Township(?), Belmont County, Ohio
died 29 August 1911, West Point, Mississippi

background:
*Thomas Jefferson Mercer wrote his own genealogy and put Fanny Frye as his mother.
He makes no other mention of her again. My speculation is that she died in childbirth- perhaps bearing him.
The date I have for her latest possible demise is the marriage date of Thomas to her sister Eliza.
One would think there would be a decent interval after her death before he married her sister.
In which case it may well have been at the time of Thomas Jefferson Mercer's birth.
http://www.familytreemaker.com/users/y/o/u/Frank-L-Youmans-jr/COL1-0338.html
for Fanny Fuller Frye born February 25, 1804?