Wow, your detailed response is massively appreciated.
I resonate with the idea that there is always an underlying cause. Though it's tricky to isolate the issue here.
Her diet is very similar to the one her brother had and he didn't have the condition.
I will check out the list you provided.
It's a pleasure. I feel for your daughter, as I know how my sister suffered from the condition.
The none invasive nature of the above recommendations make them attractive to try out.
I would never generalise when it comes to genetics. Despite having the same parents, your kids will vary in many of their traits and gene expressions. Every human being needs to be seen as genetically unique.