Thanks for the update and glad she ate well.
Prednisone... I know when Piccolo started taking this she felt better immediately. Really bumped her out of being lethargic. Of course, it has many side effects, so I imagine your vet is balancing the use of this drug with all her symptoms. (Hope that makes sense)
I do hope your vet can get to the cause of all these problems soon. Keeping you both in our thoughts today.