If Hesira ran off as you say and ended up in IT [Indian Terr.] she would not be counted in 1880 census.
General Information – 1880 census Colorado was the only state admitted to the Union between 1870 and 1880, bringing the total to 38 states. Eight territories were enumerated: Arizona, Dakota, Idaho, Montana, New Mexico, Utah, Washington and Wyoming territories. Unorganized Alaska was enumerated, but the "Indian Territory" was not enumerated for non-Indians. Unlike any previous censuses, after microfilming, the original 1880 census schedules for several states were transferred from the National Archives to various state archives, state libraries, or universities libraries. Only the original 1880 schedules for Pennsylvania remain at the National Archives. Several originals were later transferred to the National Society Daughters of the American Revolution in Washington, D.C.
Who is your g/mother and g/father? Do you have their DOB's + birthplaces?? Do you have their death certs?? Death certs should show their parents names.