Default to Apple Watch location activated under Family Setup within "Find My" app

My son's iPad is the default device that is tracked in the "People" section of the "Find My" app. I recently got my son an Apple Watch, and set it up using Family Setup. I am unable to get Find My to track his watch by default in "People". I can find both his iPad and watch in "Devices", but it's more useful that his location in "People" is represented by his Apple Watch, which he wears, instead of his iPad, which stays home all day.

I've tried changing settings in his iPad, on the phone that was used to setup the Apple Watch under Family Setup. and on the watch itself. There is no option that I can find to switch the default tracking from the iPad to his watch.

Does anybody have a solution?