In the 1881 census a John Qualtrough and his wife Elizabeth are living in Craven St Liverpool. With them is Thomas Craine 21 nephew and Theresa Craine 17 niece. These names and ages appear to coincide with some of the children of Robert Cain and his wife Elizabeth.
Robert may be the brother of Elizabeth Qualtrough.
Just a thought as there are other permutations.

Len Faragher