The serial numbers of four different B-17F Flying Fortresses seen being manufactured in this film are prominently visible in scenes shot at the Lockheed Vega factory in Burbank CA. Two of them (serial nos. 42-5845 and 42-5846) went to the air base of the 381st Bomb Group at Ridgewell, England. Both planes, later named "Whaletail II" and "Tinker Toy," respectively, were lost on the same mission of 20 December 1943. A third Fortress (42-5850), sent to the 384th group at Grafton Underwood, was shot down only a month after its arrival, on 25 June 1943, during a mission to Hamburg Germany. The fourth aircraft featured in the movie (42-5859) served with the 379th Group at Kimbolton, later being transferred to the 303rd Group at Molesworth. It survived until 20 February 1944, when it crash-landed returning from a raid on Germany with severe battle damage, being subsequently written off and scrapped. Thus not one of the four planes survived the war.
At one time the original title was "Three Smart Girls Join Up".
When the home movies are shown, there are clips from Deanna Durbin's earlier films: "Three Smart Girls", "Mad About Music", "Three Smart Girls Grow Up" and "First Love".
According to an article in the California Eagle (3 June 1943), 600 extras were employed for the scenes in the defense plant; the article named fifteen male and fifteen female extras who were African American.