"United States Census, 1930," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/X78D-M4G : accessed 12 Jul 2014), Jean Dungan in household of E Root Dungan, Rochester, Monroe, New York, United States; citing enumeration district (ED) 0149, sheet 31A, family 621, NARA microfilm publication T626, roll 1453.
"United States Census, 1940," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/KQ3S-3SJ : accessed 12 Jul 2014), Margaret J Dungan in household of E Root Dungan, Albion, Albion Town, Orleans, New York, United States; citing enumeration district (ED) 37-1, sheet 6B, family 142, NARA digital publication of T627, roll 2713.
It may be possible to confirm family relationships with Margaret by comparing test results with other carriers of her ancestors' 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 Margaret: