Oh yeah let's all force a 6 year old into child labour to teach him a lesson for basically being a child (which generally happen to be childlike with things)...
Seriously guys get a grip. The responsibility is on the parents / guardians to supervise children with expensive electronics. The OP was right to be concerned in the first instance, but I imagine had little choice in the end as the purchasing seems to have been done by his partner.
So it basically boils down to fixing the situation now with the added benefit of hindsight.
Get the Apple Care, get the iPad replaced, and then decide to keep it for the adults in the house, enforce parental control so that he can only used by the child when under supervised company, or sell it off and buy him something else.