How can I remove apple TV from my child's iMac?

My 10 year old has an iMac with screen time turned on. We have set apple TV to lock after 1 min (there is no option to have less than that, it would appear). She has figured out that if she uses the 1 min before it locks and sets it so it's playing in the background, it will keep playing regardless of the screen time lock. How can I remove apple TV altogether from her iMac?

She has also figured out various other screen time bypasses and honestly it is exhausting.

Thanks!