If your kids software is available in Ubuntu maybe? At a glance I’d wonder how power efficient it would be (my $100 Walmart tablet lasts all week with light usage, I doubt this could compare), and would have to wonder as well on gpu performance. It’s likely not optimized yet so idk I’d trust 800 mhz as enough.
I think the article sums it up best:
RISC-V computing is a promising field but best ploughed by developers, early adopters, and tech enthusiasts at present. RISC-V chip performance is improving, but it’s not “there” for mainstream adoption — yet.
It’d be a ton of fun to tinker with and if you have the money to risk I’d say go for it! But I wouldn’t buy this for a kid unless I had the extra $150 to potentially get them a normal android tablet if this didn’t work as well as hoped.