Yes, you are right that you paid attention to the safety of children on the Internet. Unfortunately, the content of the Internet is not always loyal to the children's audience. And there are many people who can harm children.
I have installed Refog Keylogger https://www.refog.com/keylogger.html
on my kids computer.
This is a simple program that records any clicks on the computer by children. And I know what programs they use, what sites they visit, with whom and what they communicate with, etc.