45 carbs for breakfast for a 4 year old seems a lot.
I can just about manage that myself and I am an adult.
If it were me I think I would go back and tak to your daughters pediatrition.
Bananas have a high carb content and are lot more healthy than cereal bars. Will your daughter eat a slice of toast?
But I do think you need to go back to the ped and tell him/her that your daughter is not an eater in the mornings and what can he/she suggest.