You may already know this, and if so, sorry for repeating the obvious. Thrush is a yeast, as you know, and yeast feed on sugar. They are typically an overdevelopment of something that is already on our body surfaces, a benign...if not helpful, organism that does daily battle with the bacteria to keep them in check. But they LOVE sugar. If she or you either one has had a recent antibiotic, that might have caused an imbalance in her chemistry that allowed yeast to predominate. So now, you might look at the formula ingredients list and be sure there isn't too much sugar. And be careful about the sugar for the rest of the family so that when she becomes table-food exclusive, she doesn't get it there. (She may be sensitive to it for some reason.) And ALL of us get too much if we eat those factory-produced foods. They put it in everything, hidden as other chemical names, to enhance taste, counteract the lack of taste if it's a lowfat product. Just stay with whole foods that don't require labels, and your whole family will benefit over their lifetime. See Dr. Oz's website, Dr. Mercola's, Dr. Weill's...all give evidence of the negative affects of sugar in the diet.