Sorry you lost her, she did sound like she wasn't going to make it, but you never know until you try.
About Corid working by starving them, I heard it interferes with thiamin uptake in the cocci, not by causing total starvation of them. I also haven't heard of them being denied all other food...
I don't know if you're supposed to use the medicine for that long, but I haven't used it so take that with a pinch of salt. Depending on what's actually in the medicine an overdose could be a problem.
Is she eating at all? You could try giving her vitamin water if you're not. If you have...