Making mistakes and learning from them is, in my opinion, part of being 12.
When my daughter says, "I don't need to study for the quiz. We reviewed in class and I've got it," I say o.k. When she puts off a chore until the last minute, I don't nudge. When she's upset by the results of these decisions, we talk about what happened and she learns from her mistakes.
"Didn't Dexi alarm?"
"Yeah, but I was only 200 and I was in art and my hands were all gross."
"O.k., but now it's over an hour later. What could you have done differently?"
"Checked after I cleaned up."
"Yeah...you'd probably be lower by now if you'd corrected, right?"
"Yeah. I'll check sooner next time."
In this scenario, she made some decisions. They weren't great ones. But we talked about it, calmly, and I'll hope that the next decisions she makes in these circumstances are better. Had I been watching that CGM graph on my mobile device in the hour before she got home*, I'm not sure I would have handled the conversation as calmly. I may not have seen the opportunity to let her take a lead in problem-solving for next time. I would have spent that hour getting increasingly irritated that her blood sugar wasn't coming down, and probably would have texted her to test and correct as soon as she turned her phone back on after school.
In the scenario we've chosen, the numbers are hers to deal with in the moment they occur. Then, help is available if she needs it.
She knows she can text or call me whenever she needs my help. The nurse is there all day at school, and my daughter doesn't hesitate to stop in her office. The Dexcom receiver reaches our bedside tables so she can have the night off from responsibility. But when she's at school or out with friends, it feels like it's time to let her flutter around outside the nest a bit. We watch carefully from a short distance ready to come to her rescue whenever needed. Once she's home we talk about any glitches that occurred and about what she could do differently next time. For her, this seems like a great way to learn all she'll need to know when those safety nets aren't around anymore.
If I had a kid who regularly ignored highs and lows I'd think differently. If her Dexcom receiver didn't give us readings when she was in bed, I'd think differently. If she was littler, I might even think differently. If at any time I feel she creeps over the line of 'learn by doing' to a place where her safety is compromised, I'll not hesitate to reconsider all of the technology available to us. Everybody's experience with diabetes is different and we all need to do what works for us at any given time.
For now, though, this is what works for us.
*If you're unfamiliar, an explanation of 2 CGM in the cloud technology options are here and here. Essentially it enables the data from a continuous glucose monitor to be sent to a designated smartphone so that there is another set of eyes on the information.