At the start of the film, set in 1939, the four sisters put up a map of the world to keep track of the soldiers' locations, but the map is contemporary from the year the film was made (1957), showing numerous nations that did not exist in 1939, for example: Laos, Cambodia and Vietnam (which would have been French Indochina in 1939), Indonesia (formerly the Dutch East Indies), Thailand (called Siam in 1939), and Pakistan (which was part of British India), among other countries.
The movie takes place in New Zealand. Toward the end of the movie, one of the sisters and her son are flying away. The registration on the aircraft is SU-AAC. "SU" is the registration letters for aircraft certified in Egypt.