More information is needed: Where in North Carolina did this family reside? Any other residences? When & where was Anna born? When & where did she die? Children's names?
The surnames BRIGHT & McDOWELL do not appear in Jo Ann Curls Page's book: Index to the Cherokee Freedmen Enrollment Cards of the Dawes Commission 1901-1906 nor in Napoleon Davis' compilation: Oklahoma Creek Freedman: My Roots. 1858-1921. This isn't intended to say Anna was not of Cherokee or Creek ancestry, just says she's not on the list(s) where one would expect to find her if there is a connection. There or other Indian Nations she might have a connection with; Choctaw, Chickasaw, Seminole, or some other.
Have you gathered census data? That's the place to start; 1930 back to 1870. Was Anna slave or free? Important to know as it will dictate how to handle the census' from 1860 back.
Hope this helps.