Enable Developer Mode on Apple Watch SE w/ Family Setup?

I have an Apple Watch SE (watchOS 10.1) paired to my phone via Family Setup. I'd like to connect it to Xcode to install apps on, but it's not appearing in Xcode's Device Organizer. Nor can I find the option to enable Developer Mode in Settings->Privacy & Security.

Note*: I do have my personal watch connected to Xcode. This would be the second watch I'm trying to build to.

Is this a limitation of Family Setup? Or is there some way I should be kicking the watch to have it recognized?