Try familysearch.org. It appears that they also had a son "Sylvanus".
https://familysearch.org/search/records/index#count=20&query=%2Bsurname%3Aburgess~%20%2Bbirth_place%3ACanada~%20%2Bbirth_year%3A1840-1875~%20%2Bfather_givenname%3Aisaac~%20%2Bfather_surname%3Aburgess~%20%2Bmother_givenname%3Amary~&collection_type=6&offset=20
Elisha W. Burgess
birth: 1857 Burlington
marriage: 08 Jan 1882 Burlington, Hants, Nova Scotia
parents: Isaac, Mary
spouse: Alcestra Marsters
Clara Burgess
birth: 1867 Burlington
marriage: 01 Apr 1884 Summerville, Hants, Nova Scotia
parents: Isaac, Mary
spouse: Tupper Sanford
Sylvanus Burgess 1949
birth: 1860 Burlington
marriage: 15 Oct 1884 Greenfield, Kings, Nova Scotia
parents: Isaac, Mary
spouse: Elva Fielding
George H Burgess
birth: 27 Nov 1857 Nova Scotia
death: 27 Nov 1912 Dedham,,Massachusetts
spouse: Fannie C. Paine
parents: Isaac Burgess
Rachel A. Burgess
birth: 1852
marriage: 12 Jan 1871 Newport, Hants, Nova Scotia
parents: Isaac Burgess, Mary
spouse: Alfred C. Burgess
