parents unknown. investigation shows Sallie was probably NOT born in Ferrisburg around 1756 because the town was not chartered until 24th of June, 1762 (in 70 shares to 66 settlers). Names of the earliest known settlers do not include a Roberts.
http://www.vermontgenealogy.com/addison/ferrisburgh.htm
Unfortunately, the settlers in the original charter are unknown - record probably burned in 1785.
http://genforum.genealogy.com/cgi-bin/pageload.cgi?walter,gage::vt/addison::665.html
Also no Roberts lived in Addison County, VT in the earliest census - 1779. There is a "Durand Roberts" in neighboring county Chittenden County, town of Fairfield. Durand Roberts was the first constable of Vergennes, VT in 1789. Eli and his son, Durand, were captured by the British in 1778. Online trees say his sons were born in New Milford, CT (1764, 1767...) Eli Roberts one of the founders of New Haven, Addison Co, VT.
However, a problem with dates -
"Abigail Durand is the daughter of Noah Durand and Abigail Riggs. She married Eli Roberts at New Milford, Litchfield, Connecticut, USA, on 31 May 1763.1
(Eli Roberts b. 14 Apr 1736, d. 11 Feb 1805 )"
1. [S226] Unknown author, Durand Family: Descendants of Dr. John Durand, A Huguenot, Born 1664, La Rochelle, France, p 31: "Vital Records [New Milford], Vol. L.R. 8, Eli Roberts of New Milford (she of Derby)."
...perhaps Eli married before, or brought a neice with him (daughter of Peter or Benjamin, also sons of Eli Roberts and Mary McKay, but who stayed in CT). There is no account of her birth in the "History of the towns of New Milford and Bridgewater, Connecticut, 1803-1882" which describes the Roberts' family origins.