This help article helps to show you how you can request further information and details for an attendee.
Find the activity you wish to view the attendees for, select view activity.
Scroll down to the attendees list and select view attendee for the attendee you wish to see the information for.
If you feel there is information missing that you require, select message attendee. Here, you can send a message to the parent of the recipient to request the information you require.
Once you have received a response from the parent, select edit attendee and add the information that was missing. Scroll down to the bottom, select the tick box and click edit attendee. This will now update the information you have for the attendee.