Family Sharing Features

Is it possible to block a child from using their phone during school hours but allow an exception for them to send/receive calls/texts from their parents/grandparents only?  We currently have Verizon Family which allows this and I love it. We are considering switching phone service and I was told to look into the family sharing since we have iphones. I don't see where you can make exceptions. It seems to be an all or none feature, but I am not sure. Thanks!