Here's the synopsis from Wikipedia:
The story focuses on two families, the Jewish Blitzteins and the Cockney Lockes. Mrs. Blitztein and Alfie Locke have adjacent stalls on Petticoat Lane: she sells herring, he sells fruit; they do not like each other. Their children, Georgie Locke and Carol Blitztein, are in love with one another. In the course of the plot, Carol is blinded in an air raid, Harry Blitztein (Carol's brother) deserts the army (failing to show up when he is mustered), and we learn that Harry has a girlfriend Joyce, who is married to another man.
Georgie comes home from the war injured and invalided, and still in love with Carol despite her blindness. They get married (her mother approves, his father does not). Immediately after the wedding, Mrs. Blitztein nearly dies in another air raid, and is rescued by Alfie in his role as an ARP warden; they reconcile. Harry goes back to the Army.