Mary was born in 1894. She is the daughter of Frank Pokorny.
Sources
"United States Census, 1900," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M3BP-1QH : accessed 30 April 2021), Mary Pokorny in household of Frank Pokorny, Midland Precinct, Colfax, Nebraska, United States; citing enumeration district (ED) 49, sheet 2A, family 28, NARA microfilm publication T623 (Washington, D.C.: National Archives and Records Administration, 1972.); FHL microfilm 1,240,920.
"Nebraska Marriages, 1855-1995," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:Q2ZL-RQCW : 28 November 2018), Frank Pokorny in entry for Frank Mihulka and Mary Pokorny, 03 Jan 1914; citing Marriage, Schuyler, Colfax, Nebraska, United States, Nebraska State Historical Society, Lincoln; FHL microfilm 2,020,710.