Please ignore my earlier post.
Since then I have found information that disproves what I posted earlier today.
Jacob and Priscilla Mosby's parents were Stephen and Alice Oneder Mosby. Stephen is the son of Jacob Mosby.
Jacob Mosby, of Cumberland Co., guardian of Jacob Mosby the younger an infant, only son and heir-at-law of Stephen Mosby late of said Co., deceased, deed to Poindexter Mosby of same Co. all that tract of land in Cumberland Co. whereon said Jacob Mosby in his life time and the time of his death dwelt containing by estimation 400 acres adj. Revd. Robt. McLaurine, Francis G. Steger, and Col. Thos. Tabb. Recites that "by decree of the general Court of this Colony bearing date at the Capitol the seventh day of May in the year of our Lord 1764 in a suit in Chancery there pendening in which Alexander Spiers, John Bowman & Company of the City of Glasgow merchants and partners were plaintiffs and Alice Oneder Mosby widow and Administratrix &c of the said Stephen Mosby deceased and the said Jacob Mosby the younger party to these presents his grandfather & guardian defendant it was among other things decreed and ordered that the said Jacob Mosby should sell" . . .the tract of land aforesaid. Oct. 22, 1764 , Cumberland County, VA, Deed Book 3, p. 525.
Alice Oneder Mosby, widow of Stephen Mosby, decd. of release of her dower in 400 acres conveyed to Poindexter Mosby, of Cumberland Co., by Jacob Mosby, and formerly belonging to her husband Stephen Mosby, decd. Oct. 22, 1764 , Ibid, p. 527.
Alice Onedy Mosby, of Cumberland Co. deed to her daughter Priscilla Mosby one horse, 2 feather beds & furniture, one parcell bed furniture, one parcell of old pewter, parcell of old chairs, parcell of old sifters & one cow and one negro man named Toney. Wit. Hezekiah Mosby, Poindexter Mosby. Dec. 14, 1764, Ibid, p. 550.
Priscilla's marriage bond states that Priscilla is the daughter of Alice Oneda Mosby.
24 Dec 1786
Know all men by these presents that we Robert GILLIAM and James Johnstone are held and firmly bound unto the Governor of the Commonwealth of Virginia in the sum of fifty pounds Current money . . . dated this 24th day of December 1786.
The condition of this obligation is such that whereas there is a Marriage Suddenly intended to be solemnized between the above bound Robert GILLIAM and Priscilla Moseby. If therefore . . .
Signed & Sealed in presence of George Watkins.
Sig: Robert GILLIAM, James Johnston
This is to certify that I have given my consent to a marriage between my son Robt Gilliam and Priscilla Mosbey.
Witness my hand James GILLIAM, 22nd Decemr, 1786.
Wit: Stephen May and Wm. Thweatt
This is to Certify that I do, Volentaley [sic] give my Consent to a Marriage between Robt Gilliam and my Daughter Presellia Mosbey, without Reserve, witness my hand Allsey Mosbey, 24th Decembor 1/86 . Wit: William Thomas (Thweatt?), John Sullivant Senr.
This is to Certify that I am Twenty one yars of age, I have given my consent to a marriage between Robert Gilliam & myself.
Witness my hand Priscilla Mosbey, 22nd Decemr 1786
Wit: Stephen May, Wm. Thweatt."
Cumberland County, VA Court Orders contain other references to Stephen and Alice Oneda Mosby including guardianship for Stephen's son Jacob.