Before searching the title of the book that started the search and resulted in finding the tragic fire that killed a mother and her four young children, I did some more investigation into the family. As often the case, what I found raised more questions.
What we know based on the newspaper articles and the death registrations:
The father was William Wonch. The mother was Mary, daughter of J. Leppard from near Markdale, Ontario. At the time of her death, she was 29 years old according to the death registration.
I didn't find any birth registrations for the children.
When I searched for the marriage of William and Mary Leppard, the closest match was a marriage of a William Wonch, aged 24, living in Collingwood, born in Ontario and a farmer. His parents were Georg and Mary Wonch to Elizabeth Jane Leopard, 19, living in Collingwood, daughter of James and Rose Ann Leopard. The witnesses were John Sproul and Bridget Leopard, both of Collingwood. 
-- The problem is the discrepancy in her name. The surname Leopard and Leppard seem to be interchangeable with some families. In the marriage record, her first name is different
It would have been helpful to see the name of the mother in the birth records. There may be baptismal records available.
The 1871 Census for a James Leppard from Artemesia Township.  It is a large family.
James, 41; Rose Ann, 40; Thomas, 22; Joseph, 19; Mary, 18; Bridget, 15; Elizabeth, 14; Rose Ann Leppard, 11; James, 9; Abigail, 8; Peter, 6; Sarah, 4; Abraham, 2. 
The family has a Mary as in the death registration, an Elizabeth as in the marriage registration and a Bridget who was the witness to the marriage of Elizabeth Jane Leopard.
I found two marriages for a Mary Leopard/Leppard in the Ontario marriage registrations with parents, James and Rosanna/Rose Ann Leopard/Leppard but not to a Wonch.
Why the name of Mary in the death registrations and not the marriage registration is still a mystery.
I went back to look at the Markdale newspaper article. The one entitled "Sad End"  but I looked at the image again. The article in "Sad End" was in column 4. Looking at the whole page, I found another article in column 1.
Mr. James Leopard, father of the deceased wife of the late Cook Teets, received the sad intelligence by telegram on Saturday night last of the terrible fate of his daughter who lived in Barrie, who, with her four children were burned to death in their beds on Friday night last . . ." 
"Cook Teets" now that name is familiar. It is the name of one of the main persons in a novel I plan to read next, An Act of Injustice by Ray Argyle. 
To be continued
 William Wonch -- Elizabeth Jane Leopard Ontario marriage registration #010087 24 September, 1877; digital image, Ancestry.ca (http://www.ancestry.ca : accessed 12 July 2017) citing microfilm MS 932 Reel 5, Archives of Ontario, Toronto.
 1871 Census of Canada, Ontario, South Grey (district 36), Artemesia Township (subdistrict g), division 1, p. 73, family 261; digital image, Ancestry.ca (http://www.ancestry.ca : accessed 14 July 2017), citing microfilm C-9952, Library & Archives of Canada, Ottawa.
 "Sad End" Markdale Standard, 11 June 1885 p. 5, col. 4
 "Flesherton" Markdale Standard, 11 June 188Ra5 p. 5, col. 1
 Ray Argyle, An Act of Injustice, Oakville, ON : Mosaic Press, 2017.
© 2017 Janet Iles