How old is your child when they’re online?
There is a reason why there is a minimum age set for online services.
It has been many years since my children were at school. However, my recent work with schools covering data protection has given me an insight about how the digital age has necessitated the inclusion of awareness of social media and other online activities as part of the curriculum, especially in primary schools. Why children should not give a false age online is one of the items that needs to be addressed.
An example: a 9 year old persuades his parents that he needs one or more social media accounts because his friends are on them already. Either he or his parents give a false age to allow him to sign up. So, online he appears to be 13, and gets access to the content appropriate for a 13 year old (one would hope). But this means that when he actually reaches 13 his online age will be 17, and he then gets content which is not appropriate to his actual age. And consider that when he is 14 he appears to be 18, the age required for access to adult content, and so on.
Hopefully your children or grandchildren are being made aware of this fundamental aspect of signing up to social media when they are in school. Either way, please do make sure you are also aware of it if your children are active online.