Therein lies one major problem. People were asked to report if they had seen anything suspicious or abnormal.
Consequently, we have a very limited picture of what normal activities were going on.
Who could determine what was and what was not suspicious or abnormal? It would have been a monumental task for a police force to plough through statements in an effort to pin point areas of interest to them.
Something which the observer might have considered mundane and not worth reporting could actually have been pivotal if in the hands of the police.
Also,
a) there was the problem of a changeover in holidaymakers, many of whom returned home at the weekend
b) the police were in ignorance of the Smith sighting until a fortnight after the event
Therefore in a fairly static population any anomalies would have stood out like a sore thumb; visitors would not have known the difference.
However since there were no reports of a child wandering about on her own it is unlikely there were any innocent sightings of such.