I am answering my own question as someone on the Evans board had proof that Esther Evans was originally Esther Knowlton of Halfmoon, Saratoga Co., NY. John Evans died before the 1860 census, but by that time Esther had remarried, a John Griffin in Burlington, Lapeer Co. On the 1850 census page, she and Mr. Evans are living with their daughter, Harriet Earl. The next family in the census also contains a daughter, Elizabeth Warren, her husband John, and children. By 1870 she has a new husband too, Seth Willey. In 1870 Esther is widowed a second time and is living with her daughter Mary and son-in-law, Edwin M. Roberts. So almost all of the Evans family had immigrated to Lapeer Co., MI, leaving son Ephraim K. Evans back in New York.