The marriage certificate for Hannah Chamberlain arrived. See attached. I'd say this is definitely the Hannah Stephens that my source was thinking about. Her father's name, address & profession match. Her husband Arthur is a "Fruit Salesman" but his father is given as "Chief Steward Merchant Service", a merchant sailor, which may have influenced Arthur's decision to enter the merchant navy when war broke out & he was killed at sea in 1940. Thanks to John for the leads!
