I had the dubious joy of setting up a miserable low powered android excuse for a kids computer from VTech over christmas.
It's so low powered the slow reaction time made me believe it wasn't working for a while. The screen is tiny, the ergonomy crappy, and the software is gahh...
To give the kids something they could actually use without bringing tears to the kids and their parents, I set up an old laptop with Linux Mint Cinnamon.
A nice, easy, and quick installation.
I added Seb's IP hosts file, and in Firefox, in addition to the basics (Ublock Origin,Decentraleyes,etc.) I set the search engine and default page to Qwant Junior. I also added some bookmarks like WebJunior.
With Mint's library of games and educational software, their mum can add more things later as required as only she has the root password.
For the same price of the VTech toy, you can get a refurbished Thinkpad X240 from Backmarket, set it up the same way, and actually have something useable.
UPDATE: The kid loves the old laptop, and the VTech ...thing has been relegated to the dustbin of Christmas past. Win!