First of all, it is very understandable that you are concerned and feeling overprotective. Most of us diabetic mothers have been there and share those same worries and concerns. The good news is that I don't think ear infections alone are a sign of diabetes and it sounds like your doctor doesn't either. If your child were to develop diabetes, he would experience other symptoms that would be very apparent to you, including excessive thirst and urination, lethargy, etc. If it would make you feel better, go ahead and check his blood sugar, but I wouldn't encourage you to get into that habit because you can drive yourself crazy.
We all know that there is a hereditary component to diabetes and that makes us worry, but we also know that diabetes shows itself very loud and clear and that if it is going to happen, there is nothing we can do to prevent it. So, my advice is to enjoy that very happy playful baby. He will grow up very fast and be filling out those college applications before you know it, hopefully without the added burden of diabetes. But if it should happen, and believe me, I know that is something that you pray every day doesn't happen, he will have a great role model and a lot of support. Ultimately, we all have to remember, that although diabetes is a horrible disease, it doesn't have to stop us from having a full and rewarding life.
In the meantime, I'm still supporting JDRF in their search for the cure and hope that there will be a cure in our lifetime!
So go play with that baby and enjoy every minute with him!