First off, congratulations to your stepdaughter [and probably also to you and her father] for relatively good A1c reports. Then, I very strongly encouraging her to take on more and more responsibility so that she doesn’t constantly need you to make HER decisions. Although I’m not in the medical profession, I do try to encourage those I informally coach to allow their kids to gradually assume responsibility as they become aware of their condition and T1D management; I base my suggestions on my own 60 years “learning experience” managing diabetes. If she has siblings she could involve them by her “teaching” them and in turn she will learn her own management; from age 4 our granddaughter began checking my blood and wanted to poke my finger more often than I’d formerly do, and by age six was giving me injections. My management improved!
My pump has various alarms including a “Check BG” - if hers has that, set it to beep a certain number of hours after her latest bolus. I also set my “auto off” at six hours so if I don’t touch the pump within that time it will beep and vibrate; yes, 4 AM us six hours after my 10 PM evening BG check and snack.
She should be aware enough now to calculate her own corrections but a while let her ask you for confirmation- recently I’ve been asking my wife, we’ve been married more than a half century, when I’m high in care I’ve overlooked a reason so that I don’t over-correct and go low. The three of you could make a game of carb-counting must do the research to be “judge”.
Keep in mind that she is at the age for wild unexplained BG swings so don’t chastise her overly and remember that result of a BG check [notice I refrain from saying “test”] is a reference point for HER to make any necessary change or adjustment. Positive encouragement, and remind her that soon she will be in high school and wanting to do everything the other kids are doing and go places with her friends; there isn’t a thing that she can’t do [because of diabetes] and she can live a full life.
Mom & Dad, enjoy your daughter, let her “fly free” while you remain silently n the background and she will sour and bring life to you.