Blocking Chat

Hello all!

Our 10 year old daughter has discovered the world of online chatting. Unfortunately, it has become a problem. I can log into the "admin tool" and block easy sites like discord etc. But I am having trouble with YouTube (go figure!). Using Chromes Inspection tool, it appears the chat content comes from https://www.youtube.com/live_chat?(then a long string of characters.). This appears to be consistant with several items I checked out. My question is; can I filter out www.youtube.com/live_chat*? I do not want to block YouTube totally and she needs to access some videos for school work etc. I just want to nuke the chat function. I know I could use some fancy ad blocker or script to nuke just that container, but I need to block the chat on multiple laptops, cell phones, Nintendo's etc. The only "cure all" would be to block it at the router...