Final answer:
No specific individual is historically recorded as being allowed to visit Anne Frank while in hiding, except for the trusted helpers from the Dutch underground resistance who provided the secret annex residents with necessities and news.
Step-by-step explanation:
The person whom Anne Frank was allowed to see once while in hiding is not explicitly mentioned in historical records. However, Anne kept a diary during the two years she was in hiding with her family in an annex in Amsterdam. The only individuals who were allowed to visit the Franks were a small group of Dutch friends who were part of the underground resistance providing them with food and news. This close-knit group of helpers were the only connection the family had with the outside world, and there is no specific mention of Anne being allowed to meet anyone from outside this circle. It is important to note that visiting the annex would have been dangerous for both the visitors and those in hiding, as it could lead to discovery by the German authorities.