It is possible that George and Narah are living together in 1871 as Fordgw and Sarah Hodgkinson even though they don't marry until 1874. Their children Harriet and George (Fordgw) turn up in 1881, Harriet with George and Narah, George with Grandma Caroline. It definitely looks like Sarah on census though. Still it explains why George is not widowed on marriage cert, and why George and Narah otherwise disappear in 1871.
Good thinking!