Elizabeth Warren lived in Norman until she was 11 years old, when the family moved to Oklahoma City. Norman is just a short distance south of Oklahoma City, essentially a suburb, so people from Norman would have frequently traveled to the bigger city, such as Elizabeth's mother.
The photo shows some epicanthic fold which is east asian, and she also has a broad nose which is characteristic of the southern part of east asia such as Malaysia and Philippines.
The Philippine Islands, a U.S. possession, provided a few immigrants to Oklahoma in 1910–30. By 1930 most of the twenty-one resident Filipinos worked as cooks, servants, and butlers in larger towns. However, at least two were professionals. In the last half of the century, because of new immigration laws, the state's Filipino population grew to 3,024 in 1990 and 4,028 in 2000. Of those, 1,261 resided in Oklahoma County and 642 in Tulsa County. Oklahoma City is in Oklahoma County.
So if a woman in that era got pregnant through hanky panky or through rape, what would she say to her husband? In Oklahoma, there was a ready story for any slight oriental look, which was distant Cherokee Indian ancestry. A little white lie to keep the conjugal peace. I expect that a DNA test will show that Pocahontas is actually one quarter Filipino.