The documentation that John,Sr. was son of William is the 1748 court record where John was executor of William's 1748 will.
1748 Feb.10 Will of William Pruit (who died at the age of 97) proved by John Pruit, executor. Charles Walden and Mary Shirley witnesses. (Order Bk 1748-50, part 2, p 8; & Colonial Caroline- p473). 1748 Feb.10 Mary Shirly and Charles Walden were witnesses to John Pruit proving William Pruit's will.(Mary (Pruett) Shirley may have been William's daughter who married Thomas Shirley)
Thadues had at least two sons Thadues,Jr. and Richard Prewit, who died at Valley Forge.
1774 Sept8 Thadeus Pruitt(Jr?) & Mary Pruitt recorded (will of Thadeus Sr.?) Mary Pruett was granted letter of administration for the estate of Thadeus Pruett,dec'd.
1776 Thadeus Pruitt,Jr. listed as a Colonial Soldier of Va ((Revolutionary War) (VA Magazine 1, p. 386) from The Pruett Family by Haskell Pruett, Ph. D.
1778 Oct24. Richard Pruet was mentioned in a letter ofEdmund Pendleton to Wm. Woodford..Edmund asks if inquiry can be made about his widow neighbor's son Richard Pruet who was in Capt. Nathan Reid's Company of the 14th Regiment. Rumor has it that Richard Pruet is dead or in the hospital.((Letters of Edmund Pendleton Vol. 1 page 274). (The widow neighbor could be Mary Pruett, wife of Thadeus Pruett who died in 1774.) There is a Muster Roll record that says Richard Prewit was drafted Feb 1778,died July 15, 1778 in the hospital at Valley Forge.
There is very little on Benjamin except he was with his brothers and fined for not attending church and was in two law suits.
1790-1805 James City County had almost no Pruett records until a Benjamin Prewet who paid taxes on 136 acres in James City County from 1790 to the time of his death in 1805. Could this Benjamin(b1731)be the Benjamin from Caroline?.