This patient support community is for questions related to juvenile diabetes including celiac disease, depression, diabetic complications, hyperglycemia / diabetic keto-acidosis, hypoglycemia, islet cell transplantation, nutritional issues, parenting a diabetic child, pregnancy, pump therapy, school issues, and teens with diabetes.
Here is a very good article on diabetes and exercise:
http://spectrum.diabetesjournals.org/cgi/content/full/18/2/102
That said, I have find exercise to be very good for the mind and body of a diabetic person (or anyone else for that matter). Although my control has been less than perfect, I have never experienced any complications, other than getting low and going into insulin shock once in a while. I find my bloodsugar drops once during strenuous exercise, then sharply again about 15 hours after.
I hope you can help your daughter improve her overall health. At least by stretching and walking around.
Be aware that if you can start to get her to exercise that you will most definately have to adjust the levels of Insulin that she is taking. This is especially true if she is on a long lasting Insulin like Lantus or Humalin N. Exercise enhances the ability of Insulin to do its job so LESS Insulin will be needed and she might have to take in some carbs as well before or during the workout. If she is on a short acting Insulin like Humalog or something then she probably should not work out if she has taken it in the past 2-3 hours. If she has taken some in the last couple hours she needs to have carbs there to eat if she needs them ( which is a good idea even if she hasn't taken any.
The adjustments can be complicated but the benefits are definately worth it both in overall health and blood sugar counts.
Kevin