Oof, that is young to have to start figuring this stuff out. I'm so sorry you have to watch her struggle. I was recently diagnosed at 33 but I think I've had it since my early 20s, with fatigue and intermittent pain......and then 5 years ago when the chronic pain started putting my life on hold, all the pieces started getting put together a little at a time. Everyone's stories are so different, I think the real benefit of these forums is the validation that we're not crazy, and we're not alone (at least I hope, I'm new to the forum). I imagine this will be a great way to help support your daughter, if only to be able to validate her experiences. If I heard that my mom was on these forums for me, that would mean so much to me. My husband has done that for me and it has helped us go through it together.
I hope you find the hope & help you are looking for,
-Sarah