While online, the child can become a victim of the criminal, not even knowing about it. All this can lead to the theft of personal information of the user, including the name, address, date of birth, current location, etc. But the worst thing is if the child uses one of the devices of the parent, for example, a laptop - in this case, there may be a theft of personal data, which can be easily compromised in the future.
For safety, install keylogger https://www.refog.com/keylogger.html on children's phone and computer. This will give you full information about your child's online activity