Elizabeth was born in 1846. She passed away in 1924.
Sources
"Ontario Deaths, 1869-1937 and Overseas Deaths, 1939-1947," database with images, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:JD29-BX8 : 19 December 2020), Elizabeth Yonge Mercer, 26 Aug 1924; citing Windsor, Essex, Ontario, Canada, , Registrar General. Archives of Ontario, Toronto; FHL microfilm .
"Find A Grave Index," database, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:QV23-VMWF : 13 September 2020), Elizabeth Young Archer Mercer, ; Burial, Toronto, Toronto Municipality, Ontario, Canada, Saint Johns Anglican Church Cemetery; citing record ID 63721108, Find a Grave, http://www.findagrave.com.