nostr is not for kids unless there was a heavily moderated kids only relay
Discussion
I wouldn’t let my kids on 4chan either. Doesn’t mean the internet is broken. Just means you have to curate your kids internet.
nostr:npub19dn7fq9hlxwjsdtgf28hyakcdmd73cccaf2u7a7vl42echey7ezs2hwja7
has the following relay in his profile. I havent dug into the effectiveness or how it works. 
Yes, nostr:npub1zafcms4xya5ap9zr7xxr0jlrtrattwlesytn2s42030lzu0dwlzqpd26k5
nostr-filter-relay is configurable relay with several parameters. If you are familiar with filter.nostr.wine then you might easily understand how nostr-filter-relay work.
There are many examples (with different parameters relay) documented in USAGE https://github.com/atrifat/nostr-filter-relay/blob/main/USAGE.md
In nostr:npub12z8jsett3k6rv9fa2guau5p540qr2xuvjzkr8e432mglafjt99sqkw9zmx case, it can support her works actually as shown in illustration example:
"I want to make a specialized Nostr client for non sfw content creator (pornhubstr). I don't need any sfw/regular content"
wss://nostr-id-relay.hf.space/?content=nsfw
And vice versa:
"My Nostr client is s*cks. It doesn't have any settings or toggle button to filter Non SFW or sensitive content"
wss://nostr-id-relay.hf.space/?content=sfw
Users can freely customize relay settings using different parameters based on their needs. Feel free to test them. 🙂
Are you not kids?
My kids on nostr so I might be a bad parent 🤣. But I’ve never shielded the world from him and at 15 he’s brilliant and kind
My kid is 7. I wouldn’t give him a phone let alone damus. He gets obsessed and unruly. I might be ok giving him a linux box.
Even then someone would find a way to corrupt it. Humans are gonna human. Creeps are gonna creep. At the end of the day, it's up to parents to regulate what their child has access to.