Hi Elmar,
Your current structure is like an example below?
- TestPage (PageMenu item)
- -- Doc1 (child)
- -- Doc2(child)
On TestPage you have a repeater which renders the content of Doc1 and Doc2. You want to have indexed only text presented on TestPage, is that correct? Now lets say, you will create a new page called Doc3 with some information in it, this information is printed on TestPage, however you can't display this text in search results even if you rebuild your index? Could you please check CMS_Search task database table, are there any records? Also you might want to try to inspect your index with LUKE tool, so you can see what data are in your index.
Also what hotfixes have you applied? Please consider applying the latest hotfix in order to have the latest code-base and all known bugs fixed.
Regards, Roman Konicek