This has always been a problem.
If the user chooses NOT to turn on GPS, or I cannot force it on, then the data I collect is invalid - since US government rules demand lat/lon values with each record created.
Enabling GPS makes it available for all apps (I assume) - even the ones your kids don't want enabled for tracking them.
I think, as developers, we need an APP ONLY permission - where we need access to GPS. All other apps would have to ask, demand, register the same permission. Google would have to figure that one out...
The only alternative now, if GPS isn't enabled, is to close the app, or keep demanding that GPS be enabled... Both options stall data collection.