That's really sad and tragic. There are like 50, or some other large number, things that affect blood glucose levels and we control 2 or 3 of them(insulin, food, and exercise). Your wife's friend may have done everything correctly and still had blood glucose that was too low.
This is why I sleep so much better since getting a CGM, it's life changing because one can make data driven decisions that minimize risk and be alerted when it's time to pay attention. It helps take away cognitive load that lessons the risk of burnout too.
I can't imagine what it was like as a T1 before them.
I was diagnosed T2 about 2.5 years ago, and worse a Freestyle Libre (not technically a CGM, but very close) for the first 6 months or so. Very useful for figuring out how I'd react to certain things, and I've got things pretty well under control now (A1C ~5.5)
That's awesome. Yeah, like anything using the data to make better decisions is the way, otherwise there's no point. Even as a T1, if my BG is high, I will generally(not always) eat less carb or none for a meal. Plus the changes in insulin dosing. It's just easier and injected insulin is so much slower than what the pancreas can do(both in time to react and duration)
This is why I sleep so much better since getting a CGM, it's life changing because one can make data driven decisions that minimize risk and be alerted when it's time to pay attention. It helps take away cognitive load that lessons the risk of burnout too.