I understand the whole "slowly slowly" approach to her treatment (she's young, let's not be too invasive etc etc' but surely there's a timeline for these things and for the dr to say 'ok it's now been 72h since she's been on X. Nothing's shifting. Let's have an ultrasound to check out where the poo has got to'. Or whatever. This will do lots to your sense of control and anxiety levels.
When my child was admitted to gosh, he was there for 2 weeks. Within those 2 weeks they'd narrowed their diagnosis down to what he's finally got (it was a difficult diagnosis to get to). But to get there, he had a bone marrow aspiration (under GA, he was 4), he had so many blood tests, ultrasounds of many body parts and Drs by his bedside every day. Play worker would come every day as well and because he wasn't infectious (or had a low immunity like the others on his ward), he had the play room to himself and lots of stuff. Although I was going mad with worry (does he have cancer or a really bad diagnosis), I felt that he was in the best hands and I did my best to facilitate discussions. I never once felt left alone.
I feel that with little diagnosis, your Drs seem to be just trying things out and 'see how it goes'. I realise that this is of course just my reading of your situation (you may not wish to share it here) but I do hope that there is some recourse or some plan B or indeed plan C for moving forward.
Anxiety tends to build up when people don't know what's going on. You've gone through so much, as has your dd and your whole family. It is not unreasonable to expect some sort of answers or at least a sit down with the dr to say ok, what now??? Even if they don't have answers.... 