I found a document from the Central Rappahannock Heritage Center Archives regarding the estate of Lewis Cobbs dated 1843. It lists the children of Lewis Cobbs. Nelson Cobbs is listed as a son. Lewis' widow is listed as Susan W. and I think she is likely a later wife and not Nelson's mother. Other children listed are: Overton, Lynch, Fleming, Terrell, Lewis V., Harriet, and infant son Robert T. It mentions a Napoleon P Luck as spouse of a late daughter. I believe her name is Elizabeth from a marriage record I found.