From her Social Security Record:
Mattie Ozella Wren [Duncan]
Gender: Female Race: White Birth Date: 10 Sep 1882
Birth Place: Leflore City, Oklahoma
Father: Sam Duncan Mother: Emma Brazier
Notes: Jun 1937: Name listed as MATTIE OZELLA WREN
In the 1900 census in Indian Territory she is listed as white and living with relatives: "United States Census, 1900," database with images, FamilySearch (
https://familysearch.org/ark:/61903/1:1:MST3-83T : accessed 20 January 2022), Mattie O Duncan in household of James H Gibson, Township 6 N. Range 27 E., Choctaw Nation, Indian Territory, United States; citing enumeration district (ED) 88, sheet 32B, family 636, NARA microfilm publication T623 (Washington, D.C.: National Archives and Records Administration, 1972.); FHL microfilm 1,241,851.
She appears to have a brother, Joseph, born in Arkansas in 1870.
This is probably her father, Samuel: "United States Census, 1870", database with images, FamilySearch (
https://www.familysearch.org/ark:/61903/1:1:MNC6-K14 : 28 May 2021), Samuel Duncan in entry for Joseph I Duncan, 1870. The Brashier family is found two houses away.
There is nothing to suggest an Indian connection, this is one of thousands of white families who moved to Indian Territory.