I recently heard and read about “Freetime for Alexa,” which is like a kids’ version of Alexa that can be used on Echo Dot devices. My young kids have Fire tablets, where they log in as Freetime users. They’d like to use Alexa. I know I can use Alexa on the Fire tablet, when signed in as an admin/regular user.

https://forums.developer.amazon.com/questions/184720/alexa-for-kids-on-fire-tabletalexa-for-kids-in-fre.html