That's such a cool idea! I don't have kids but if I someday do I'll probably steel your idea. I feel like the digital era makes it "to much" for kids, and having a limited, physical library was a better experience overall.
Walled gardens suck, so I built this for audiobooks and kid-story podcasts for my kids. No tonies for us, and my kids have way more control over what they listen to. Same base setup with the reader, just different media sources and player targets.