Hello. I'm not a medical professional, just the parent of a kid with diabetes. As a fasting blood glucose result, 80 is on the low end of the ok range, but it is in the ok range.
If your daughter will develop diabetes, or just hypoglycemia, there is nothing known that you can do to prevent it. You can keep your family, daughter included, more healthy through exercise and a better diet with more fruits and grains, for example, but that won't stop hypoglycemia in your daughter. That being said, you may want to verify with your doctor on what range your doctor was basing the diagnosis on, because an 80 score doesn't seem to be in the range. Just remember that I'm not a medical professional, though, just a parent like you.
It's absolutely something to be concerned about, but if your daughter doesn't show any more symptoms it likely isn't as big of concern. Just learn the symptoms and keep a watch out, and ensure that the hypoglycemia doesn't progress.
also do I need to be concerned with this turning into diabetes