Seeing as how you didn't give any information re your grandfather, I worked on his twin, Mary.
Informant: Mrs Edward Dodge
Registered: 1 July 1893 Griffith & Matchewan Renfrew
5 March 1888
Mary, female, father Joe Bovin [scratched out], mother: Lenii Leclare.
Father's last name has been transcribed as Bossin but on 1891 census she is listed under Bovin.
The Dodges must have registered Mary when they adopted her.
Did not find any other children b 5 March 1888 in Renfrew but it stands to reason if her father was Joe Bovin/Bossin, then so was your grandfather's.
1891 census Matchewan Renfrew
Edward, 26, Ont
Angeline, 22, Ont
Mary Bovin/Boven, 3, Ont, lodger, both parents b Ont
She is with the Dodges on 1901 census with birth 5 March 1888.
1906 she married Paul Napoleon LeClair and on the marriage registration is just says 'both parties illegitimate' where the parents names should be.
I looked in the Ontario Druoin Collection but doesn't look like Renfrew is on it.
Try Google for church records.
Harriet's  father is listed as Milton McCoy and he was living next to Dodge's on 1901 census and he has a Harriet,8, living with him.
Maybe Mary's descendants know something about her past.