"...Any info would be appreciated...."
You are so correct. Information you need to provide to us!
Great Grandpa first name. Where in Canada was he in 1851.
Wife? Other children?
Do you know the daughter's names?
Question" If Great Grandpa was born in 1836 he would be 25 years old in 1851. How old could the two daughters have been in 1851? Even if Great Grandpa had married at the age of 14 or 15 which was not unusual back then the daughters would be 8-11 years old in 1851.