The first records I discovered concerning Frances Keziah Marshall referred to her children, Marshall and Elizabeth. On November 24, 1820 a Richard Marshall, aged 63 and living in Muskingum County, Ohio stated that there were at that time living with him his wife Keziah and two grandchildren: Marshall and Elizabeth Stutts. 
Looking for further information, I discovered a record for the marriage of Adam Stults and Franky Marshall performed by J. K. McCune on March 14, 1809 in Muskingum County, Ohio. In the record, the bride is listed as “Mrs. Franky Marshall,” and I have no explanation for this unusual use of the title “Mrs.” 
We can learn a bit more about Frances Keziah by following the records of her children. Looking at census records for 1880, we find a Marshal Stultz with birthplace listed as Pennsylvania for father and Virginia for mother. This is consistent with his grandmother, Keziah saying in her 1847 application for a widow’s pension that she married Richard Marshall in 1784 in Virginia (in the County of Spotslyvania, she thought). Some genealogies show Frances Keziah as born in Spotsylvania, VA; this is a reasonable assumption, but I know of no evidence to verify.
I found a record of military service for Adam Stultz indicating that he enlisted on June 19, 1812, served in the 19th Infantry under Captain (Wilson) Eliott, and died in action on May 5, 1812. This would have been during the Seige of Ft. Meigs, during which the 19th infantry participated in Miller’s charge to capture the British battery near the fort.  I then found a military pension record showing Marshall and Elizabeth Stultz as the heirs of Adam Stulz, 19th infantry, death date May 5, 1813.  The date of enrollment was April 14, 1818, suggesting that Frances Keziah was dead by that time, since she would otherwise be the one entitled to the pension as a widow. (Note: It was necessary to view the original record to get the correct date of enrollment.) The place of residence for Marshall and Elizabeth was Muskingum County, Ohio, which is consistent with them living with their maternal grandparents, Richard and Keziah Marshall.
Some family trees show Adam Stults born in Pottsville, Schulykill, PA to Henry Jacob Stultz (1770-1836) and Magdalene (1770-1848). It’s difficult to know how much weight to give this, since I’ve seen no citations of supporting evidence.
The spelling of Stults is unsual, but it seems to have been used somewhat consistently in earlier records for Adam Stults and his children. It seems possible, then, that there is some connection between Adam Stults and a few others of that name found in records of the same time period for Ohio. There is a grave record for Henry Jacob Stults at Find A Grave, but this person and his family seem to have lived around Sandusky, which is some distance from Muskingum County.
 Pension Application of Richard Marshall, transcribed by Will Graves (http://revwarapps.org/w7391.pdf : accessed 15 September 2015).
 “Ohio, County Marriages, 1789-2013,” database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:2QHJ-PP2 : accessed 15 September 2015), Adam Stults and Franky Marshall, 14 Mar 1809; citing Muskingum, Ohio, United States, reference ; county courthouses, Ohio; FHL microfilm 865,142.
 Averill, J. P. (1886). Fort Meigs: A condensed history of the most important military point in the Northwest, together with scenes and incidents connected with the sieges of 1813, and a minute description of the old fort and its surroundings, as they now appear. Toledo: Blade Print. and Paper Co., p. 28. (http://archive.org/stream/cihm_02206#page/n33/mode/2up : accessed 15 September 2015).
 Ancestry.com U.S., The Pension Roll of 1835 [database on-line]. Provo, UT, USA: Ancestry.com Operations, Inc., 2014. Original data: United States Senate. The Pension Roll of 1835.4 vols. 1968 Reprint, with index. Baltimore: Genealogical Publishing Company, 1992.