I am fairly certain that Marcy (AKA: Mercy) Stroud was the daughter of John Stroud Sr. and Abigail (the widow) Bates of NH. John Stroud Sr. b. Natick, MA, son of William Stroud. John was in Nelson, NH during the Rev War and was a Rev. War vet. Marcy's half brother was John Stroud Jr. of Stamford, VT. Several of the names of Marcy and Arca Whipple's children fall perfectly in line with this line of Whipples (Abigail, William and Joseph Stroud Whipple).
More info here on the Marcy Stroud family that I posted recently: