I'm no expert, but you are giving her great supportive care. She's on Corid for day two, correct?
I think you could still try some electrolytes--just no B vitamins recommended with Corid, right? Or is sugar contraindicated, too?
Is she besties with anyone she could have as a safe roommate?
I wish I had more ideas... Short of an antibiotic (and I wouldn't know which kind to try--I'm assuming this is either reproductive or a GI related infection, but that's still just a total guess!!!) I wouldn't know what else to try.
Hang in there, Esther.