Her daughter [Sarah Jane (Price) Black (7 Feb 1852-19 Sep 1930)]'s death certificate named her mother as Mary Jane O'Neill, who was born in Nova Scotia. Mary Jane (O'Neill) Price was married to A. Wellington Price. ---
Most people don't marry or have children before age 15. 1852-15=1837. Both parents, A. Wellington Price and Mary Jane O'Neill would have been born before 1837.
I suspect that the information was received from a relative, and not accurate for her daughter's information. Margaret was born in 1869 according to records, but her mother supposedly died in June of 1866.
https://archives.gnb.ca/Search/Cemeteries/Details.aspx?culture=en-CA&Key=72181 - New Brunswick Cemeteries for PRICE, Arthur W (d. 1871-Feb-19 at age 54] "Relationship: h/o Mary J, Cemetery: New Canaan, Queens County " 1871-54 =1817 for approx year of birth)
https://archives.gnb.ca/Search/Cemeteries/Details.aspx?culture=en-CA&Key=72206 - New Brunswick Cemeteries for PRICE, Mary J (d. 1866-Jun-20 at age 58). "Relationship: w/o Arthur W., Cemetery: New Canaan, Queens County." 1866-58=1808 for approx year of birth for Mary Jane (O'Neill) Price. (b. approx 1808 at Nova Scotia- 20 June 1866)