Gertrude married Andrew Knerr, son of Abraham Knerr Jr. and Eva Elizabeth Knoegler, after 1807. (Andrew Knerr was born on 23 Feb 1774 in Lowhill Twp., Lehigh, PA 2, christened on 13 Mar 1774 in Lowhill Twp.: Lowhill Reformed Church, Lehigh, PA 2 and died about 1810 in Grapeville, Westmoreland, PA.)
1 Roberts, Charles Rhodes, History Of Lehigh County, Pennsylvania, Volume II (Allentown, Pa., Lehigh Valley Pub. Co., 1914. 3 volumes, illustrated, maps. Prepared by a committee appointed by the Lehigh County Historical Society; chapters contributed by various writers.).
Lowhill Reformed Congregation, Northampton County, Pennsylvania, 1769-1881 (http://www.ancestry.com).