The school needs to have a clear, simple and easily enforceable rule about what can be brought in for the breaktime snacks.  If they deviate from the rule for one child they will be forced to spend time dealing with the rantings of all the parents who are demanding rights to crisps, chocolate and biscuits.  The 'medical room under supervision' clause is so the school can support the needs of diabetic pupils.  If I were you, I'd give her a banana, which is as high in carbs as a pitta bread.

2 chgs!!! why don't you prepare breakfast at home and make her (daughter i mean) eat? she doesn't have to eat at school... she hase a coice... and if you want your daughter to eat a healthy food you should take care about it by yourself

It seems a bit harsh but at least they are trying to get the kids to eat healthy foods. You never know alot of other kids probably eat loads of rubbish at home.
What about a nice fruit salad for the morning snack, and ensure she has a good filling breakfast before school.
It would be hard though, as I would be so hungry by morning tea time and I usually had some crackers or fruit and yoghurt. But that was usually because I didnt have breakfast.