Purchases are linked to the account that made them and can’t be shared between profiles. Follow these steps to restore purchases made with the same Amazon Kids+ account: 

1.    Launch the Kids+ app

2.    Switch the account to the Kids+ account that is linked to your purchase.

3.    Launch the app and let it download completely.

4.    Enter the in-app Settings Menu.

5.    Tap on Restore Purchases (from the child’s Kids+ profile).

All purchase made with that same Kids+ account should immediately restore.