Seems that Smart Family on an Apple Watch requires that it be paired to a phone.
Given that the Series 6 can be setup as a standalone device, it pretty much makes Smart Family useless.
Are there any plans to develop a standalone Apple Watch Smart Family app?
It's great to know that you're interested in using Smart Family to manage the usage of an Apple Watch. This service is intended for one main device on the account to monitor and manage the other lines. We offer other ways to monitor your usage beyond Smart Family, and these are generally going to be much better when you have a single line instead of several: https://www.verizon.com/support/tools-for-monitoring-usage/ . As for the location option that Smart Family can offer, your Apple Watch would already have that in the Find My Device app that comes with it.