How do I change a person's role in family sharing?

casie160 wrote:

we just recently changed phones around in our household and so now the phone that was being used as our "house phone" is now my son's. currently that phone is listed as Adult. is there a way to change it to a child account??

There are various issues awaiting here:

For your immediate question, and which will still leave you with issues, see above replies, and see if that helps. This is, however, the wrong approach.

Your son should have their own Apple ID, and the iPhone reset and reloaded using that Apple ID, as sharing an Apple ID ends badly, particularly if there are other users of that same Apple ID. Notifications and two-factor and other details will be sent to the expected places, but not where you probably want them sent when working with a shared Apple ID.

Switching ages on an Apple ID, and again, the wrong approach: Update the birth date associated with your Apple ID - Apple Support

If they're younger than 13 years or so, you'll need to change the Apple ID with the assistance of Apple. Or (better) switch the device to their own Apple ID. And this is the wrong approach.

Switching Apple IDs is basically this procedure: What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support This will resolve this issue, as well as avoiding the mess that is a shared Apple ID.

we just recently changed phones around in our household and so now the phone that was being used as our "house phone" is now my son's. currently that phone is listed as Adult. is there a way to change it to a child account??

Family Organizer: Settings > Apple ID > Family Sharing > Role

Types of Family Sharing members - Apple Support

Are you using a device logged in as the organizer?