In the scenario that kuschku suggested, taking a photo of each child and following them home to record the location (once) would probably not count as stalking

In the scenario that kuschku suggested, taking a photo of each child and following them home to record the location (once) would probably not count as stalking IMO but its difficult to say. In the UK it has to happen twice, according to Wikipedia https://en.wikipedia.org/wiki/Stalking https://en.wikipedia.org/wiki/Stalking