Diet in fructose malabsorption:
Foods to avoid: honey, apples, pears, plums, pruines, peaches, cherries, dates, figs, and dried fruit in general, any sorbitol (in some sodas, and "low calorie products"), any product containing HFCS...
It's also possible that she can't tolerate some foods that have nothing in common..so she would need to make a list of foods after which she is fine, and which make her bloated.
Ovarian cyst, or cancer of any kind is not likely to cause bloating.
It would also help, if you can say, in what time after the meal she gets bloated, does she have diarrhea, what's the color of the stool, is any mucus or undigested food in stool, does she burp, have flatulence, does she have early satiety..
1. Lactose intolerance. Lactose free diet: no dairy products, and any other product with lactose - would help in 2-3 days.
2. Fructose malabsorption Low-fructose diet: no fruits or any fruit product, no sorbitol and HFCS (read labels) would help in 3-4 days
3. High-fibre food (legumes: beans, peas...) Well, this would be obvious...
4. Small intestinal bacterial overgrowth (SIBO) (breath test would reveal increased hydrogen in expired air - test is done by gastroenterologist).