@tekkenism

delete games from the lists
Using 7.2.2-Reloaded, downloaded image file for RPi4 from Recalbox.com

It is not possible to delete games via Emulationstation in Recalbox 7.2.2, so either you are not using the official 7.2.2 version, or your cousin is deleting directly from your SD card.

If you are not using the latest official version (7.2.2 at the moment), we cannot support you.
If you are using the latest official version, but your cousin is knowledgeable enough to delete games directly on the SD card, there will be no configuration available in Recalbox to prevent this.