This seems to be one of those threads that could go on forever more without a conclusion. It could be John and Jeanette were never married, John could have been married previously (he is a lot older than Jeanette) Jeanette could have been married previously and the first two children hers from that marriage, or they could have been illegitimate and have taken the Bennett name. Without the birth records for those 2 children, Herbert and Doris it may be impossible to take this thread further.
Just a note that I did check out a Jeanette Janet Molenkamp born 17 Oct. 1868 36 Woodstock Street, West Ham, Essex who also went to British Columbia and married surname Fisher. A family tree entry gave her date of death the same as Jeanette Bennett Fisher which was incorrect as Jeanette Molenkamp Fisher died 6 th July 1933. So another one discounted. Have advised the tree owner and gave them a link to the correct record so that they can correct. (hopefully

)
Still think it is worth an e-mail to Toronto Public Library to see if it is possible they can locate any death/obituary information for John Bennett between 31 st March 1901 and June 1904.
Will bow out for now Tom but will obviously post anything constructive if I find anything.
Regards
Sandra