This is speculative, but I think Mary Theresa Ertl may have been the daughter of Henry Ertl, b 20 Nov 1893, Blumenthal, Temes, Hungary and Pauline Magdalena Karolin Weber b 23 Feb 1896 in North Dakota, USA. Pauline married 2nd John Lefor 7 Oct 1937. John Lefor b 7 Sep 1882 in Ernsthausen, Torontal, Hungary. Mary in the 1940 census in New England, Hettinger, North Dakota.