1. Are you talking about the Timothy Miller who m. Julia Ann (Juliana) Glenn, 17 Jun 1823 in Shenandoah? If so, Duane Borden's Shenandoah Marriage (1850-1882) list 2 marriages of children of Timothy:
a. Tomas Miller to Margater Barton 21 Nov 1854 (as you mentioned)
b. Andrew J. Marston to Sarah Isabelle Miller, 29 Jul 1858
2. Same Timothy Miller filed pension claim as vet from War of 1812, having seen service as a private in "Jesse Allen's Co. Va Mil" per Ancestry.com index. Anything to be found at NARA? Or, where in VA did Jesse Allen's company hail from?
3. The Kentucky birthplace seems very weird to me. I verified tht KY was never a territory, it was part of Virginia until statehood, June 1, 1792. Early records might have lableld older events as VA where later compilers might call it KY? You know your sources better than I, but I'm discounting the KY as garble, repeated times 3 for now.
4. Some Family Trees at Ancestry.com show a William Barton b. ca. 1766 as father of a Thomas, who might name a son Timtohty who names a son after his own father, i.e., Thomas? Just speculation.
5. So at this point do you think it's more pertinent for your research that you sort out the Bartons more, or that Millers are priority. If Millers, I might need the rest of that Edinburg tree, since I didn't expand back in time too much beyond Elizabeth to Peter (Jr.) to Peter (Sr.).