www.automatedgenealogy.com shows them on the 1911 census - it looks like John the son of Stephen and Jemima came first, in 1910, with wife Ellen and children Cyril and Fanny, and then Jemima, Hilda, and Albert came in 1911.
The ones who have disappeared before the 1911 Canadian are (using freebmd)
Lilian = Lilian Elizabeth M, b. 1883 May have married 1909, to Joseph William Buckley (birth Eric J. Buckley, Dover, 1920, mmn Drake)
Mabel = Mabel Edith M, b. 1880 May have married 1906 to William Byrne (birth Leonard S Byrne b. 1913 Dover, mmn Drake)
Alice = Alice Maud(e) b. 1876 may have married 1896 to John Baxter or Herbert Edward Virgo
William Henry S. b. 1888 - may have married Winifred E Lewis in 1915 in Cheltenham - several possible children b. in Dover and elsewhere.
Charles Ernest b. 1879 m. 1906 to Beatrice Maude Hall or Kate Doble
freebmd also shows Stephen Butcher Drake m. Jemima Mercy Neeves, 1875, and Jemima's birth in 1852.
Those who went to Canada you should be able to see on ship lists at :
http://www.findmypast.com/passengerListPersonSearchStart.action