So this trip yielded two documents which have helped tell more of this particular story. One was a guardianship assignment made by the Orphan's Court in Sussex County in 1818 assigning Nathaniel Oliver, the father, as guardian of Daniel, John, Mary, and Peter. Aha! Finally we know the Oliver father. In addition this document gives us an approximate idea that Sarah probably died shortly before the time of this document (1818).
But then one has to drive from Newton, the county seat of Sussex County to Belvidere, the county seat of Warren County, to follow the trail and there more treasures were waiting to be found. Specifically a deed dated in 1827 from all the Oliver heirs selling their inheritance of their part of their grandfather's estate to George B. Voss. This document not only further identifies Daniel, John, Mary, and Peter as Sarah and Nathaniel's children, but it further states that Nathaniel died before the Mann estate was divided, so some time between 1818 and 1827.
And there was one more nugget yet to be found. In reading this deed all the way through, at the end were two proclamations from judges in PA, affirming the identities of three of the Oliver children. Specifically, John Oliver was noted as being from Luzerne County, PA, and Mary Cleaver and Peter Oliver were noted as being from Columbia County, PA. It's my assumption that Daniel Oliver was living somewhere in Warren County at the time because there was no special proclamation of his identity further noted.
Soooooo, what does this mean? It means that I started looking in Luzerne and Columbia counties in PA for Oliver's and I have not been disappointed. There are in fact some family trees out there that go from present day back to John Oliver and stop there because of not knowing his parents. And now here I come, working from the other direction, having the parents and am just now discovering their children. Isn't it amazing how this genealogy work comes full circle? I must admit I love nothing more than to watch the pieces of my puzzle falling together with the pieces of somebody else's. It sure makes every second of doing this work worthwhile.