I am a 43 year old diabetic, who was diagnosed 7 years ago with Type 1 (not always just for juveniles :-) diabetes. After three months of he** on multiple shots per day and wildly swinging blood sugars, I made the best decision of my life and got an insulin pump. I can now eat pretty much anything I want, including all kinds of things I shouldn't be eating regardless of whether or not I am diabetic. Basically, anything that you know the carbohydrate count for and how your body will absorb it (which is usually impacted by fat and fiber) you can match the insulin too almost seamlessly. Pizza, Coca-cola, sushi, cookies -- really doesn't matter.
Insulin pumps work even better for children than adults, because you can manage the fast acting insulin in .05 (5 one hundredths) of a unit. Since 1 unit of insulin for me is 21 grams of carbs, or 112 BG points, the micro management is important (kids are the same). Every pump set is good for the equivalent of about 24 shots. No more eating on a schedule, having to wake up at the same time, or worrying about what happens when I get sick and can't eat.
Sugar free is not the best solution -- some of the substitutes cause the runs, and you still have lots of high glycemic index carbs in white flour.
I'm happy to report 7 years out I have zero complications, and my labs look so good that my endocrinologist says you can't even tell from the tests that I'm diabetic.
So maybe not quite the answer you were looking for, but one that you might be interested in looking into none the less. The site insulin-pumpers.org has a section especially for children and about 5000 people willing to provide advice.