For me, it's a very odd solution to a problem that we have to answer a question before allowing our webcam to be used. I would never set my webcam and mic to be allowed by default, and if I ever give my laptop or device to anyone to search for something I'll put them in a private browser for their privacy aswell as mine.
Either way, I can probably not even begin to understand the responsibilities of being a parent, but if some safeguard is put into this one site, what about the next site you visit that has a similar idea? You're in the same situation again - and there's no shortage of websites for people to chat to each other via webcam.