My kids have had the Kindle Fire tablets for a few years. The hardware is pretty underpowered but they were super cheap. However the Amazon software on top of it is fucking TERRIBLE. To allow your kid to access a web site, you have to log into the tablet with your own PIN, twice for no reason, then wait for the horribly laggy app to load, then add the site, then go back to the kids' login.
My hopes for this Kindle reader wouldn't be high.