It is believed, but not confirmed
that the Desire Sedgwick who married "Mr Pomeroy"
is the "Kesiah" Sedgwick who married Titus Pomeroy.

417
Desire Sedgwick  [Samuel Sedgwick / Deborah Higgins]
b. December 8, 1758, Tyringham, Berkshire, Massachusetts
bp December 31, 1758, Tyringham, Berkshire, Massachusetts1 (6F-3)
d. May 19, 1835, [Sand Lake, Rensselaer, New York]5
bu Sand Lake, Rensselaer, New York, Sand Lake Union Cemetery5
m. 1778, Titus Pomeroy

Titus Pomeroy  [Ebenezer Pomeroy / Rachel Searle]
b. October 10, 1757, [Southampton, Hampshire, Massachusetts]
d. February 17, 1846, [Sand Lake, Rensselaer, New York]5
bu Sand Lake, Rensselaer, New York, Sand Lake Union Cemetery5

Census Records:

1790 NY Columbia, Kinderhook

Desire Sedgwick's youngest brother Elijah Sedgwick (1769-1861) was interviewed in April, 1854 by George Sedgwick, first of the Sedgwick genealogists. He told George that his sister had married "Mr. Pomeroy."

Book Excerpt: History and Genealogy of the Pomeroy Family, Albert A Pomeroy, page 265 as quoted in A Sedgwick Genealogy: Descendants of Deacon Benjamin Sedgwick compiled by Hubert Sedgwick, page 173. (Hubert added the quote in that book because one or more of the descendants of Benjamin married Pomeroy, and he wasn't sure who Kesiah Sedgwick was.)

"Titus Pomeroy (Ebenezer, Eldad, Caleb, Eltweed) b. October 10, 1757, m. 1778, Kesiah Sedgwick, who died November 19, 1836. They moved from Northampton, Mass., to Rensselaer County, N.Y., in 1781. He served two enlistments during the American Revolution, registering from South Hadley, Mass., as private in Captain Moses Montagne's Company, April 19, 1775, and Captain Benjamin Benney's Company, March 13, 1777. He died at Sand Lake, N.Y., February 17, 1846; buried at Sliter's Corners by the side of his wife."
US GenWeb/Rootsweb: Northampton, MA - Marriages from first record to 1840, by Groom:
Pomeroy, Ebenezer 3rd Searle, Rachel 1/2/1740

Book Excerpt: Genealogies of Connecticut Families, "Selected and Introduced by Gary Boyd Roberts", which contains genealogies "Extracted from the New England Historical and Genealogical Register", Volume III page147:

paraphrase: Titus Pomeroy b. 1757 m. 1778 Keziah (or Dinah) Sedgwick, was Town Clerk in Norwich, Massachusetts. Titus was son of Ebenezer, son of Eldad, son of Caleb, son of Eltweed.

Notice of Intention to Marry was published at Southampton, Hampshire, Massachusetts on December 12, 1778 by Titus Pomeroy and "Kezia" Sedgwick.6

According to the burial records, the wife of Titus Pomeroy was named "Desiah" not "Kesiah."5

I am convinced that Titus Pomeroy's wife was Desire Sedgwick. The age is right; the location is right. Even the burial record is right! Desire is said to have married "Mr Pomeroy." Also, some records list the daughters name as Kesiah, some as Desire. From where did "Kesiah" come? There appears to have been a Keziah Pomeroy born in 1758, daughter of Joseph Pomeroy and Abigale Searle, who married a Daniel Smith. Were Joseph Pomeroy and Abigale Searle brother and sister of Ebenezer Pomeroy and Rachel Searle?

Titus Keziah/Desire Pomeroy apparently lived in Norwich, Hampshire, Connecticut for an unknown period of time. THeir two youngest children are listed as having been born there. Where are the records of the church they attended? The children's birth or baptismal records? They may tell us something, but let's find the originals, not transcriptions, so we can see how it's actually spelled.

Children:

Demaris Pomeroy (4171)
  b. October 19, 1779
  d. 1870, Westerlo, Albany, New York
  m1 October 1800, Reuben Hunting (b. September 1778, Westerlo, Albany, New York) Kesiah/Desiah/Desire Pomeroy (4172)
  b. 1781
  m. John Hudson
Titus Pomeroy, Jr (4173)
  b. September 5, 1783
Jesse Pomeroy (4174)
  b. August 27, 1785
Silas Pomeroy (4175)
  b. 1786
  lived 1861, Thompkins, Jackson, Michigan
Asenath Pomeroy (4176)
  b. 1789
  m. Luther Otis of Fredonia, Chautauqua, New York
Quartus Pomeroy (4177)
  b. July, 1794
Harvey Pomeroy (4178) (twin)
  b. October 28, 1799, Norwich, Hampshire, Massachusetts
  lived at Westerlo, Albany, New York
Milton Pomeroy (4179) (twin)
  b. October 28, 1799, Norwich, Hampshire, Massachusetts

More about Desire Sedgwick:

NHCHS collection Box 6 Folder I sheet 18

Likely sources fo more information:

Census records for Titus Pomeroy:

1790 Norwich, Hampshire, MA "Pomroy"
1800 Norwich, Hampshire, MA
1810 South Hadley, Hampshire, MA, another at Roxbury, Norfolk, MA
1820 Norwich,Hampshire, MA
1830 Norwich, Hampshire, MA "Pomroy" age 50-60 indicates b. 1770 -1780
1830 Hartland, Niagara, NY
1840 Hanover, Chautauqua, NY

Film 879901
Norwich Massachusetts Town Records 1797-1834

Sources:

1. The Sedgwick Collection (MSS B46) at the New Haven Colony Historical Society papers of Hubert Merrill Sedgwick, Francis Morris Sedgwick and Frederick J Sedgwick,
genealogists of the family of Robert Sedgwick (1613 - 1656)

2. Census records, any of those indicated.

3. West Hartford, Connecticut, Town Records

4. West Hartford, Connecticut, Congregational Church

5. Interments in Rensselaer Co., NY Cemeteries
part of the Rensselaer Co., NY GenWeb
these records:
SurnameEFirstnameDeath_DateAgeWife/HusbandTownCemetery
PomeroyDesiah19 May 183576yTitus PomeroySand LakeSand Lake Union
PomeroyTitus17 Feb 184688y,4m,7dDesiah PomeroySand LakeSand Lake Union

6. Southampton, Massachusetts Town Records
"...Marriages and Inten_____" [last part illegible on film] Town of Southampton"
available on LDS Film 0892587 Item 2
extracted April 6, 2004 by Dennis Sedgwick at LDS FHC Los Angeles"
"Titus Pomeroy and Kezia Sedgwick both of Southampton Published Dec 12, 1778"