They Met at Midnight (1946)

Anna Neagle is a World War II W.R.E.N., the counterpart of the American W.A.V.E., who encounters Michael Wilding in a blacked-out Piccadilly during an air raid. They get married and have a two-day honeymoon before she is sent to Singapore. The ship, on which she leaves the doomed-fortress of Singapore, is torpedoed, with all hands posted as drowned. Not quite. She's cast away on an unknown South Sea island for three years with a company of sailors. Wilding, unaware of this circumstance, marries again, this time, to an American girl, and they have a child, and then, Anna returns.