L.Q.
It could be something you are or were eating that is effecting her. Yes she could be allergic or just extra sensitive to the food or if it is something spicy or acidic that could cause it too. Same thing was happening to my son so I tried some formula & changed my diet. He did better on the formula (Good Start DHA/ARA) & then when he went back to the breast he was fine. So I think he may have been sensitive to something I was eating (too many onions I think).