If you are sure your daughter goes to the toilet during interval and lunch breaks, there must be a problem, so you should take her to your GP. No healthy child, whether diabetic or not, should need to ask out of class to go to the toilet. Ok there may be the odd occasion, depending on what drinks have been consumed, or even the weather, but if a child has gone to the toilet during a break, they should not have to go again as soon as they're back in the class.