Hmmmm....well I haven't got time right at the moment to chase this one out but....is there any slim chance this might be John and wife Mary?

Note that only one of those girls is indexed as STEPdaughter....I haven't tried to find this lot on SP yet....
Registration Number: 625/1
Registration district: Bothwell
Civil Parish: Bothwell
County: Lanarkshire
Address: Edinr & G Road Bellshill Dr Wilson's Ld
Household Members:
Annie Cail age 7, dau, b. Bothwell, Lanarkshire
Catherine Cail age 4, dau. b. Bothwell, Lanarkshire
Helen Cail age 12, dau, b. Bothwell, Lanarkshire, Occupation: Nurse
Mary Cail age 16, stepdaughter, b. Bothwell, Lanarkshire, Occupation: Cotton Weaver
Mary Cail age 14, dau, b. Bothwell, Lanarkshire, Occupation: Cotton Weaver
James McAllan age 2, son, b. Bothwell, Lanarkshire
John McAlur age 30, head, b. Ireland, Occupation: Mason's Labourer
Mary McAlur age 35, wife, b. Ireland
Hugh McCanville age 35, lodger, b. Ireland
Best wishes
Jean