I used to use Cocoon some time ago for this exact reason, it was pretty efficient. Source: almost 3 years ago

Most half-decent routers/wifi setups these days include some form of parental controls and/or device-level management. You can also use Google or Apple's family controls (https://families.google/families/ or https://www.apple.com/nz/families/ respectively). Source: 5 months ago

Set up Google Family which includes a Family Calendar; use that for all appointments. (Experienced mom tip: set up a Gmail account for your son, so you can claim his name, if possible. Add his email to the Google Family as well). Source: about 1 year ago

It's more affordable if you can coordinate a google family group. Source: about 1 year ago

Did you set up that Gmail account yourself, or is it attached to theirs? I set up my kids' email addresses so they would be able to register to play games like Minecraft, but they were under a family plan, so they are mine and I can search them if I find it necessary, including things like history. So, who set up the account? If it is one you've been using a while, as a minor, they might be able to. Not in... Source: over 1 year ago

Tried Support chat and he told me NOT to add a family member at https://families.google/families/ but to do it through the YTTV app (an option that doesn't exist). Source: over 1 year ago