Welcome to BYC! She looks pretty sick. Can you take her to a vet?
Vet search links:
If you can't take her to a vet, you might want to read this:
It might be a good idea to have a few of their droppings checked at the vet for worms, or you could go ahead and treat for gapeworm with SafeGuard for 3 days. Sorry for your loss. A necropsy could help you find out if she had gapworm or something stuck in her airway, if you still have the body. If you cut open the trachea, gapes can be seen as red Y-shaped worms. Aspergillosis ( afungal infection from mold that can spread throughout the air sacs and organs) could also be a possibility. The state vet is also able to do a complete necropsy. Here is a link for that: