Update on Cinnamon: Good news! After examining her, the vet was very pleased. She said her lungs sound much better, her nose is much better (ya, I know, it's a bill). The vet now gave her a 90% chance of getting better. This is ever so much better, 'cause a couple of weeks ago she said "there is always a chance" and refused to give me a number.
Cinnamon is eating and drinking much more. She breathes almost normally with only some medium to mild effort to pull air in (seems to get it out ok). When I put Cinnamon out today for a little bit she even ran a few steps and seemed quite lively (which is new). She bobbed her head at the other ducks.
Thank you all again for your support!!!