So far here's what I'm thinking about Dora. Need more evidence to prove.
1880 Waterford, Dakota, Minnesota John Gibbs45 born about 1835 NY, parents b NY, gardener Eliza Ann Gibbs29 born about 1851 in Illinois, parents b NY Dora E. Gibbs11 born about 1869 in Minnesota Charles Gibbs6 born about 1874 Minnesota Franke Gibbs1 born about 1879 Minnesota
John Gibbs certainly has an interesting life story - including a period when he went to Panama and from there on to California!
BOOK - HISTORY OF DAKOTA COUNTY,MINNESOTA published in 1882 "WATERFORD TOWNSHIP. John Gibbs was born in New York in 1823. He lived in his native state until 1844, then went to Michigan, thence to California, via the isthmus. After working in the gold mines some time he returned to Michigan, thence to Minnesota for one year; was also in the employ of the government in Nebraska a few months. In 1867, returned to Minnesota and made his home for two years in Northfield, then removed to Waterford and purchased his farm, having since been engaged in agricultural pursuits. Married at Northfield, in 1869, Eliza Wells. They are the parents of three children: Dora, Charles and Frank."
from the Dalby Database: John Gibbs born 1819 died 23 April 1898 buried Northfield. Spouse Elizabeth Wells. Born in N.Y., Came Northfield 1867. Spouse Elizabeth Wells. Born 1848 died 23 Feb 1914 LINK: http://www.dalbydata.com/user.php?action=cemsearchresultshttp://www.dalbydata.com/user.php?action=cemsearchresults
So far, this family is not sounding very much like Dakota/Sioux. Everyone so far has been migrating in the usual pioneer direction, from the east, moving west. To be a member of the Dakota nation one would not expect that direction of migration.
We need a copy of Dora's birth, marriage, or death certificate, or an obit, or the like, to ascertain if this Dora is "your" Dora.