I could find no Brights in Louden Co in 1900. Nor in 1880, It is likely she was raised elsewhere. Their marriage record names her as R E Bright. Do you know what her first name might have been? It is possible this is her family.
1880 United States Federal Census Name: Rebeckey Bright Home in 1880: Hughes Mill, Loudon, Tennessee Age: 13 Estimated Birth Year: abt 1867 Birthplace: Tennessee Relation to Head of Household: Daughter Father's birthplace: Tennessee Mother's Name: Nancy Mother's birthplace: Tennessee Marital Status: Single Race: White Gender: Female Household Members: Name Age Nancy Bright 51 Magie Bright 21 John Bright 18 Nancey Bright 16 Rebeckey Bright 13 Charles Bright 10 Marthey Bright 6