Leslie, You are right she was a daughter of Anthony Alderfer, married Johannes Schenck - ( John Shank) b.6-17-1761 York, Pa. he was baptised 6-28-1761. died 12-16-1838 in Wilkes Co., Ga. Mariah "Mary" Anna born circa 1764 ( obituary states she was age 73) Montgomery Co.,Pa.she died 5-20-1837 in Wilkes Co.,Ga. Their children were : Henry - b. 6-27-1784 George - b. 12-22-1798 John - b. 1789 Felix - b. 1-1-1800 Rachel - b. 1804 m. 8-22-1824 Wilkes Co. Robert Frazier. Mariah "Mary" - b. 2-28-1806( believed to be living with Rachel in 1840) Margaret - b. 1796 m. Thomas Jennings.
I am related through the Shanks, but my immediate family is the Alther's of Shenandoah & Page Co. Which was Alderffer.