Sandra, looks like the Ethel Hilton you found in Dallas County Iowa, born 1889, is named Ethel Marion Hilton.
1900 Dallas County, Iowa Mary Hilton b Nov 1860 widowed Clarence b Feb 1879 Leonard b Feb 1886 Ethel b Jan 1889
1920 Salmon, Lemhi, Idaho Charles H. Heidner 35 born in South Dakota, merchant, hardware store Ethel M. Heidner 31 born in Iowa Dorothy M. Heidner 10 ND Elizabeth C. Heidner 7 ND Carl H. Heidner 4 ND Glenn L. Heidner 6/12 ID
1930 still in Salmon, Lemhi, Idaho Charles is 45 and Ethel M. Heidner is 41
Social Security Death Record Ethel Marion Heidner [Ethel Marion Hilton] Social Security #… Birth: 31 Jan 1889 in Iowa Death: 20 Jan 1983 in Los Angeles Mother's maiden name: Taylor Father’s surname: Hilton