My thoughts regarding Mary, the wife of William Butler, parents of Joseph, Spencer, Charles, et al.
I am working on a theory that she was Mary EMMONS, daughter of Joseph Emmons, who's father was Charles Emmons.
Charles Emmons fled legal trouble in Westmoreland County, acquiring a survey for land in what was then Richmond County (later King George and Prince William, but now Fauquier County) by 1715 (his tract is mentioned as adjoining Joshua Butler in Butler's 1715 grant).
As with a number of families who settled next to one another in Fauquier (Rust, Berryman, Fields, etc), the Emmons' and Butler's came from the same part of Westmoreland.
The children of Joshua whose spouses we know (Dorcas m. Thomas Welch, Christopher m. Mary Catherine Martin, John m. Elizabeth Beach, Mary m. Thomas Stone) all wed the sons and daughters of near neighbors, which implies that William would have done the same. I have proven that Charles Emmons' property bordered Joshua Butler's land to the northwest.
Charles Emmons' known son Joseph Emmons was administrator of his 1725 will, so he was probably born around 1700. Since we know that his son William was born around 1720, Joseph was probably born a bit before the turn of the century.
Joseph Emmons has numerous children in online family trees, including a "Mary" who is way too young, being born around 1768 (married William Embry). The majority of the children in these trees are, in fact, born after 1740. This is not a biological impossibility, but it seems unlikely that Joseph started having children around 1720, but had most of the when he was an old man near his death bed (he died in 1767). This tells me that we have an incolplete list of children who would have been born in the 1720's and 30's.
My thought is that Mary was one of them. The evidence is circumstantial at best, and is based upon naming-patterns and continued connections between the families.
1) William and Mary's first born children were Joseph, Spencer and Charles. Neither "Joseph" nor "Charles" are known names in the Butler family heretofore, so they seem to have been brought in through this marriage. If my theory is correct, "Joseph" and "Charles" were Mary's father and grandfather respectively. AS to "Spencer", some researchers posit that Mary was a Spencer, which is where that name came into play. This is possible of course, but William Butler's sister Mary (Stone) also named a child "Spencer", which leads me to believe that it was just a popular, or known name in that region.
2) The Butlers and Emmons' remain in close geographic proximity in western and sounthern Fauquier (along the Culpeper border) throughout the 18th century. William Butler is one of six men paid out of Joseph Emmons' estate in 1767 (with Gaven Lawson, Thomas Harwood, James Crap, Joseph Odor and Thomas Barber). Plus, in October of 1773, appears as a witness for William Emmons (her theoretical brother)Mary Butler in his Fauquier County court case against John and Ann Oder.
NOW. All this is tentative and circumstantial, but I think we can all agree that barring the discovery of some "Magic Bullet" document which proves it one way or other, circumstantial "best case" scenarios are probably all we're ever gonna' have.