Earlier quoted context omitted.
As a parent, I consider myself the "end user" of my child's device, not my child. That I might be looped in on any messages sent or received by this device is not at all a leak, it's a convenience—much like how I can receive messages sent to me on my phone and my laptop.
It's very creepy that you want to eavesdrop on your child in that way, in my opinion. This is the micro version of governments wanting ubiquitous surveillance.
Am I entitled to know when my pre-teen child has received a message that contains a potentially explicit attachment, or text which matches the traits of child grooming? Hell yes.