Sounds like you are making progress.
I would work on giving her coconut oil 2 times a day. I like to give it directly as refrigerated chunks - mine will eat like candy.
In the photo I do see some grass and I read your description. In the photo I have an arrow pointing at a section - was that grass or possibly a roundworm?
Personally, I like to leave my birds with the flock unless I really feel they need to be separated or they are getting picked on. It's up to each of us to may the decision of separation, leaving with the flock, etc. You are there to evaluate her and how the flock is treating her.
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