Do you have a cgm?
Is she pumping or mdi? It sounds like MDI?
I do think you were unreasonable to say no to snack (D-parent here)as she could have had a carb free snack (meat and cheese?) or you could have bolused slightly more for the snack so as to correct the high?
I understand why you might not want to give another injection if MDI...but at 9 she's old enough to decide whether it's worth another injection?
I'm not sure why she couldn't eat until 6.30 if she had a snack, is it because you're worried about stacking insulin? I don't think one meal and one snack would be a concern there.
@crazymum they can go to bed before testing though. Most people night test? If my dd ate at 6.30 (ok she has cgm so the two hour test isn't relevant) I'd still send her to bed at 8 as long as she was above 6, then night test as normal.
I don't think your MIL was being U. She gave her sweets to have with dinner, so no extra bolus / injection and if she's going to have sweets the fat in her dinner would hopefully stop a huge spike, so better than having them alone!
agnurse but sweets are no different from say orange juice or cereal in their impact on blood sugar. They're not inherently bad for a diabetic child. They're very likely to spike blood sugars but fruit (especially juice), cereal, sweetened yogurt, dried fruit, even a jacket potato...could all do the same.