Hmmm- cravings for sweets, breads, pastas is definitely a clue that fungus could be present.
My experience- I suspected my UC was fungus related, experimented with an antifungal diet (low/carb, no mold/yeast foods- i.e. no cheese, peanuts, corn, mushrooms, alcohol, bananas, bread, etc.) and was considerably better within a few weeks. I took natural antifungals along with the diet- 2 capsules 3X/day. The diet and antifungals did put me in "remission"; still going strong. That was 5 years ago. I don't take the antifungals routinely anymore, although I take them from time to time for maintenance. I take probiotics (recommend this) and an immunity booster- beta glucan.
Diflucan should not be a problem short term. It cracks me up that doctors are hesitant to give drugs like Diflucan short-term, yet routinely write scripts for steroids, and other UC drugs as if they are seemingly "safe." If you are hesitant using a prescription drug, olive leaf extract or caprylic acid might be 2 good natural substitutes. She would probably need to go on some form of antifungal/lower carb diet, under her doctor's care, of course. A "candida" test would probably not be accurate. There are over 400 kinds of fungus that can cause disease in humans. Best to you and your daughter :)