Diabetes ran in my dad's immediate family. Growing up my Grandma had to watch pretty carefully what she ate, once and a while my siblings and I would have our blood sugar tested because Grandma had her tester out. There was a point for about 5 years where she was able to go off the needle and control her levels with diet, but she did end up requiring insulin again. They had the raspberry sugar candies at home and in their vehicle just in case. I tried to make sure they didn't get too old.
I won't claim to know what it must be like to deal with that as a parent, but I'd be more than happy to forward it on.