How do I make my kid’s Android phone ring even if silenced when I call him?
It might not be applicable if your kids are older, but my kid just got his first phone and I manage it with Google Family Link. Even when the phone is on silent I can make it play a sound and get him to answer a call or message. It's worked out really well for me, the one thing I don't know is if you can have more than one family device managers to manage the family's devices. It might be worth checking out at least.

I can also use it for managing screen time restrictions and other parental controls that I really felt were missing in cheap, stock Android phones.