On my self-training regimen half an hour was it before symptoms would set in. If I get too uncomfortable with my progress I look to the BB for encouragement. Walt has picked me up many times. I am healthier for this and would do it whether it improved the IC or not. I easily see how it could help others, I can see how hard it is for them to give it a try and harder still to stick to it.
Humans are amazingly adaptable and can live with and in horrible conditions.
It is comfortable to do what we're used to doing. Your daughter has nothing to lose trying this. It can't hurt, it can only help. It eventually occurred to me that I had a lot of questions that were only going to get answered if I forged ahead. It costs you nothing.