Due to a production error, Bram Vermeulen's narration and some of his singing were omitted from the 2004 DVD release, and also from the 2012 DVD re-release.
Elleke Vervat (Mies Wolke) said on the Girlscene.nl site that she was in fact a year older than the other children, but was chosen because she was very small for her age.
Some of the indoor scenes, such as at the shopping center, were in fact shot in and around Amsterdam, not at the regular location of Rotterdam.