Isaiah Guymon and Elizabeth Flinn (or Flynn) had the following known children:

1. William Guymon (11 Dec 1773-????) married Nancy Ashburn on 15 Mar 1814
in Stokes County, NC. They later moved to Lincoln Co., TN.
2. Frances Guymon (10 Sep 1776 - ????) married Felty Fry on 29 May 1814 in
Stokes County, NC. Unknown what happened to this couple.
3. Nancy Guymon (10 Sep 1778-????) married Micajah King on 4 Mar 1801.
Moved to Meigs Co., OH
4. Rebecca Guymon (20 Sep 1780-????). Very little known about Rebecca.
5. Elizabeth Guymon (10 Feb 1783-????) married Timothy Roark on 3 Sep 1801
in Stokes County, NC. Moved to Montgomery County, IN
6. Margaret Guymon (20 Feb 1785-????) married John King on 19 Jan 1830 in
Surry County, NC
7. Thomas Guymon (10 Mar 1787-20 Oct 1855) married Sarah Gordon on 23 Feb
1809 in Stokes Co., NC (additional info below)
8. John Guymon (20 Mar 1789-c1830) married Mary "Polly" Wright on 13 Aug
1811 in Stokes Co., NC. Moved to KY and many of his children to IL.
9. Anna Guymon (20 Aug 1791-c1825) married Laughlin Flinn, Jr. on 19 Oct
1810 in Stokes Co., NC
10. Richard Guymon (19 Jul 1793-Nov/Dec 1857) married (1) Anna Martindale,
(2) Elizabeth Fry, (3) Eliza Bonwell Mellote. Moved to Bartholomew Co., IN

The information I have on Thomas Guymon moved to Utah, dying in Springville,
Utah County, UT. His wife Sarah Gordon was the daughter of John Gordon and
Barzilla Martin. Sarah was born 20 Nov 1791 in Surry County, NC and died 7
Dec 1872 in Fountain Green, Sanpete County, UT. Thomas and Sarah remained
in Stokes County, NC for a few years after their marriage and then moved to
Jackson County, TN where the family appears in the 1820 Census. From Land
Grant records it appears Thomas owned at least 50 acres on on Proctor's
Creek. By 1823 the couple moved their family to Edgar County, IL. About
1836 Thomas joined the Mormon movement and in 1849 many in the family
traveled to Utah. I show the following children for

Thomas Guymon and Sarah Gordon:

1. Isaiah Guymon (15 Feb 1810-17 mar 1900) married Hannah Marie Martin on
23 Nov 1828.
2. John Guymon (28 Nov 1811-13 Aug 1896) married Nancy Davis on 15 Oct 1829
3. William Guymon (23 Jan 1815-31 May 1886) married Sally A. Hanks on 23
Dec 1834.
4. James Guymon (27 Dec 1816-22 Sep 1912) married (1) Sarah Davis, (2) Mary
Ann Couch, (3) Rhoda Lease Nease, (4) Mary Ann Boden, (5) Martha Jane Park,
(6) Christine Christensen
5. Noah Thomas Guymon (30 Jun 1819-7 Jan 1911) married (1) Mary Dickerson
Dudley, (2) Margaret Johnson, (3) Elizabeth Ann Jones, (4) Louisa Rowley
6. Martin Guymon (12 Jun 1821-2 Nov 1836)
7. Barzilla Guymon (31 Dec 1823-8 Nov 1869) married Matthew Caldwell on 17
Oct 1843.
8. Elizabeth Guymon (19 Jul 1826-3 Nov 1836)
9. Sarah Jane Guymon (11 Jul 1829-29 Aug 1829)
10. Polly Ann Guymon (11 Jul 1829-3 Oct 1912) married Robert Lewis Johnson
on 30 Apr 1846.
11 Melissa Jane Guymon (14 Feb 1833-2 Jan 1919) married Levi Gregory
Metcalf on 3 Nov 1850.

Thanks to Joel Russell for the info!