Born Ella Iola Tatman, it appears that she began using Ethel sometime after her divorce from Luther Thomas.

Iowa, Delayed Birth Records
Name Ella Iola Tatman
Event Type Birth
Event Date 26 Nov 1888
Event Place Milton, Van Buren, Iowa, United States
Event Place Milton, Van Buren, Iowa
Gender F
Father's Name Orange S Tatman
Mother's Name Elizabeth Jane Davis

Iowa State Census, 1895
Name Ella O Tatman
Event Place Van Buren, Iowa, United States
Gender Female
Birth Year (Estimated) 1889
Orange S Tatman M 33
Eliza J Tatman F 32
Ora B Tatman F 12
Clarence O Tatman M 10
Ella O Tatman F 6

United States Census, 1900
Name Ella I Tatman
Event Place Jackson Township Milton town, Van Buren, Iowa
Birth Date Nov 1888
Birthplace Iowa
Father's Birthplace Iowa
Mother's Birthplace Iowa

Scot Tatman Head M 39 Iowa
Anna A Tatman Wife F 32 Missouri
Clarence Tatman Son M 16 Iowa (Son of Eliza Jane Davis)
Ella I Tatman Daughter F 12 Iowa (Daughter of Eliza Jane Davis)
Charlott E Tatman Daughter F 1 Iowa

Luther B. Thomas and Ella I. Tatman
Name Luther B. Thomas
Event Type Marriage
Event Date 25 Dec 1906
Event Place Milton, Van Buren Co., Iowa, United States
Gender Male
Age 21
Marital Status S
Birth Year (Estimated) 1885
Father's Name Daniel Thomas
Mother's Name Carrie Bell Chaunell
Spouse's Name Ella I. Tatman
Spouse's Gender Female
Spouse's Age 18
Spouse's Birth Year (Estimated) 1888
Spouse's Father's Name Scott Tatman
Spouse's Mother's Name Mary Jane Davis

United States Census, 1910
Name Luther B Thomas
Event Place Swan Lake, Hayes, Nebraska
Birth Year (Estimated) 1887
Birthplace Iowa
Father's Birthplace Iowa
Mother's Birthplace Iowa
Luther B Thomas Head M 23 Iowa
Ella T Thomas Wife F 21 Iowa
Muriel E Thomas Daughter F 2 Iowa

United States Census, 1920
Name Luther B Thomas
Event Place Oak Creek, Saunders, Nebraska, United States
Gender Male
Own or Rent Rent
Birth Year (Estimated) 1886
Birthplace Iowa
Father's Birthplace Iowa
Mother's Birthplace Iowa
Luther B Thomas Head M 34 Iowa
Ella I Thomas Wife F 31 Iowa
Muriel E Thomas Daughter F 12 Iowa
Raymond L Thomas Son M 9 Nebraska
Dorothy M Thomas Daughter F 8 Nebraska
Virginia B Thomas Daughter F 2 Nebraska

Iowa Births and Christenings
Name Myrl E. Thomas
Gender Male
Christening Place Van Buren, Iowa
Birth Date 21 Mar 1908
Birthplace Grove, Davis, Iowa
Father's Name L.B. Thomas
Mother's Name Ella Tatman

Iowa Births and Christenings
Name Muriel Eliza Thomas
Gender Female
Christening Place Davis, Iowa
Birth Date 21 Mar 1908
Birthplace Pulaski, Davis, Iowa
Father's Name Luther B. Thomas
Mother's Name Ella Iola Tattman

United States Census, 1930
Name Ethel Thomas
Event Place Fremont, Dodge, Nebraska
Marital Status Divorced
Birth Year (Estimated) 1888
Birthplace Iowa
Father's Birthplace Iowa
Mother's Birthplace Iowa

Ethel Thomas Head F 42 Iowa
Dorothy Thomas Daughter F 18 Nebraska
Virginia Thomas Daughter F 12 Nebraska

United States Census, 1940
Name Ethel Thomas
Event Place Ward 3, Fremont, Fremont City, Dodge, Nebraska
Marital Status Divorced
Relationship to Head of Household Owner
Birthplace Iowa
Birth Year (Estimated) 1890
Last Place of Residence Omaha, Douglas, Nebraska

(The above census indicates that Ehtel was a resident of the Baltimore Hotel in Fremont. She was listed as the owner with several other residents listed as lodgers)

United States Social Security Death Index
Age 85
Given Name Ethel
Surname Thomas
Birth Date 26 Nov 1888
State Nebraska
Last Place of Residence Douglas, Nebraska
Previous Residence Postal Code 68144
Event Date Apr 1973