Her name may have been Mary Lulu? From Familysearch.org
U S Census, 1930 Bald Knob, White, ARK
head Joe Masterson M 57 MO
son Clarence Masterson M 25 MO
son Lee Masterson M 18 MO
US Census, 1920 Scott, MO
self Joe B Mastson M 47y IL
wife Mary L Mastson F 37y MO
son Clancy R Mastson M 14y MO
dau Pearley E Mastson F 12y MO
dau Earl H Mastson F 12y MO (? Earl HESTER)
son Lee E Mastson M 7y MO
dau Della M Mastson F 5y MO
dau Gladys C Mastson F 10m MO
U S Census, 1910 Kelso, Scott, MO
self Joe Masterson M 36y IL
wife Lula M Masterson F 29y MO
son Clarence Masterson M 5y MO
dau Earl Masterson F 2y MO
dau Pearl Masterson F 2y MO
son John Masterson M y 3m MO
Some of these sites may be helpful in researching American Indian ancestry.
https://familysearch.org/learn/wiki/en/American_Indian_Genealogy http://www.ncai.org/tribal-directory