food intolerance network - food intolerance network - lactose fructose histamine

My 7 yo DD was recently diagnosed. I have been avoiding giving her fructose and want to determine which fruits she can tolerate and which she shouldn't have at all. I understand that this is mostly trial and error? I printed the fructose chart (a great place to start! thank you ) So for something like banana, which may or may not be tolerated well... How long after eating it will a stomach ache start, or does that vary, too? I can only go on what she is telling me, and she's a very high spirited, energetic girl, so it's sometimes difficult to get an answer unless she "stops" to think for a minute. But she rarely stops Unfortunately stomach aches have just been the "norm" for her until now. Thanks for any input as to how to gauge her level of tolerance