I've had type 1 diabetes since I was six years old (23 years old now).
Hardest part about the disease is the routine itself. Testing blood sugar often, for your or your kid's curiosity will help a lot with finding the right groove for eating and dosing. For me, I take a baseline insulin every 12 hours, and then take a different insulin depending on how many carbs a meal or snack has. While the diabetic specialist gives me the baseline numbers for dosing, the info from blood testing helps them and me the most in the long run.
The most basic advice I can provide besides testing a lot:
Soda and juice are good for treating low blood sugar quickly. Fast acting carbs and sugar. Overdoing it though can cause a low to spike up to a high. As a kid I felt low blood sugar really easily, constant lows throughout the week aren't good and can cause those sensations to go away.
Don't know if kids get flu shots regularly, but for diabetic adults its highly recommended to get flu shots every year. If your kid can't hold down food or fluids, you'll need to go to the ER or urgent care for an IV, due to not being able to control blood sugar with food.
Depending on the insulin and dosing, cutting down on high carb or high sugar snacks is highly recommended. While blood sugar can be treated with insulin, its never instantaneous and having a consistent schedule with meals makes dosing a lot easier.
Test before bedtime, every time. Unless its baseline insulin, be very cautious with dosing before bedtime. Waking up with high blood sugar is a lot more preferred than the alternative.
