Many genealogies have Mary's parents as William Humphreys and Mary Melb or on some trees Mary Melb Summers. That is based on an old Daughters of the American Revolution application. I can now say for certain that lineage is not correct.
Her parents are William Humphreys and Rachel Spencer. And Williams parents are Samuel Humphreys and Grizella Cavet. If anyone has any questions about this, please contact me at firstname.lastname@example.org I'd be happy to lay out my evidence, which includes dna matches.
"United States Census, 1850," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M8RM-KVV : 12 April 2016), Nancy Arie in household of Joseph Arie, Knox county, part of, Knox, Illinois, United States; citing family 389, NARA microfilm publication M432 (Washington, D.C.: National Archives and Records Administration, n.d.).
"United States Census, 1870," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M647-TC1 : 17 October 2014), Nancy Aris in household of Wm M Roush, Illinois, United States; citing p. 27, family 192, NARA microfilm publication M593 (Washington D.C.: National Archives and Records Administration, n.d.); FHL microfilm 545,729.
"West Virginia Marriages, 1780-1970," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:FRF5-CL4 : 4 December 2014), Joseph A...Y and Nancy Humphreys, 1832; citing Greenbrier, West Virginia, p3, county clerks, West Virginia; FHL microfilm 595,040.
It may be possible to confirm family relationships with Nancy by comparing test results with other carriers of her mitochondrial DNA.
However, there are no known mtDNA test-takers in her direct maternal line.
It is likely that these autosomal DNA test-takers will share DNA with Nancy: