Here are a few more children that I found using different search criteria.
Rachel May Burton, born 12 Jul 1896 in the Township of Joly, District of Parry Sound, daughter of James Burton, farmer, and Rachel Haggart, residence Lot 8, Concession 12, Joly.Roll # MS929 133.
Rachel May Burton, age 18 (born 12 Jul 1896 in South River, Ontario), married Cecil Leo Caverley, age 19 (born 14 Feb 1895 in Severn Bridge, Ontario), son of Albert Caverley and Kathleen Fitzgerald, on 29 Jul 1915 in Whitney, Ontario.Witnesses to the marriage were John Hanson and Samuel James Burton, both of Whitney, Ontario.
Thomas James Burton, born 28 Apr 1899 in the District of Muskoka, son of James Burton and Rachel Haggard. Roll # MS929 146.
Frank Ingals Burton, born 1 Jul 1901 in the District of Muskoka, son of James Burton and Rachel Haggard.Roll # MS929 154.
[Charles] Elmer Buron, born 7 May 1905 in the Township of Bracebridge, District of Muskoka, son of James Burton and Rachel Geneva Haggart.Roll # MS929 174. Note: The roll page on which this entry was found was torn and hard to read.I could not make out the first name correctly so I have made an eductaed guess that it is Charles.