She is probably very very dehydrated- if she isn't drinking and has diarrhea. Try and get some fluids in her- try some Pedialyte or similar children's rehydration drink to get those fluids and electrolytes back in her.
Keep her warm.
Do you have an emergency vet around? They can put her on IV fluids- this is very serious.
My puppy went into this condition, after her very severe diarrhea. We rushed her to the emergency vets, they put her on IV fluids and she was absolutely fine and safe. Then we could treat the underlying problem- campylobacter and giardia.
It's the loss of fluids etc. that is really going to the absolute danger in the case of diarrhea, not necessarily the underlying cause, so I really would stress hydration hydration. Try syringing Pedialyte or something similar.
Jen