That is fabulous she is doing better! I was thrilled to read that. If she is eating now that sounds really positive. All the best of luck! Could this be the staggers? from perrenial ryegrass toxin from old pasture? Staggers can cause tremors.
I think it is related to the ergot fungus in old grass ... someone else may know more. And there is good info on the web under staggers. But if the sheep gets stressed (any mild stress) she loses her balance and can have tremors. With calmness i think they get over it after a while, maybe three weeks or so. Its awful to see. Their eyes get a very weird look to them. And they have to be kept away from ditches, creeks etc
My understanding is the staggers is ussually from longer seedhead so farmers tend to top their paddocks. But it seems staggers can be from a number of different toxins or vit /min deficiency. White muscle disease is prob worth looking up. I might be talking through a hole in my head, but it may help!