Is 'Blitz' based on a true story? What's real in Saoirse Ronan's World War II drama

In "Blitz," Saoirse Ronan stars as Rita, a mother who sends her son away from London during WWII bombings. The film portrays lesser-known aspects of war, blending fiction with historical events. The storyline sheds light on the resilience of women and the struggles faced during wartime.