The 1850 USA census seems to indicate she was attending a seminary in Ohio.
Interestingly two Day families were listed as next door families on the list. Were they where she met her future husband? Timothy was not listed in the family names at that timeMaltby-309 13:04, 4 September 2022 (UTC)
Mary Jane was born about 1832. Mary Jane Johnson ... She passed away about 1862.
"Find A Grave" sources her cause of death as consumption.
United States Census, 1870," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M62C-T1M : 17 October 2014), Mary J Day, Ohio, United States; citing p. 215, family 1685, NARA microfilm publication M593 (Washington D.C.: National Archives and Records Administration, n.d.); FHL microfilm 552,708.