Can an Apple Watch with cellular be set up/activated by a Verizon supported iPhone but managed via Family Sharing on a second Mint Mobile supported iPhone?

Hello Screen_time_app_limits_dropped,

You are able to setup the Apple Watch using a different wireless carrier plan. If your daughter does not have an iPhone, then you can follow the steps here: Set up cellular on Apple Watch - Apple Support that are also listed below to set up the cellular on the watch.

Set up cellular on a family member's Apple Watch

You can set up a cellular Apple Watch for a family member who doesn't have their own iPhone. If your cellular carrier supports the use of a managed Apple Watch, you're given the option to add the watch to your plan during setup. Look for the option to set up cellular, then follow the onscreen steps. If your carrier doesn't support it, you might be able to use an alternative carrier. 

If you don't set up cellular on your family member's Apple Watch initially, you can do it later with these steps:

1. Open the Watch app on your iPhone.

2. Tap All Watches, tap your family member's Apple Watch, then tap Done.

3. Tap Cellular, then tap Set Up Cellular.

4. Follow the instructions for your carrier. You might need to contact your carrier for help.

To see the phone number assigned to your family member's Apple Watch after you set up cellular, go to Settings on the watch, then tap Phone. 

Best regards