I used the word "duck" to search the emergency forum here are two threads I found ... I looked through the first 3 pages of results.
https://www.backyardchickens.com/forum/viewtopic.php?id=264033
https://www.backyardchickens.com/forum/viewtopic.php?id=239251
Probiotic info found here: http://www.shagbarkbantams.com/page8.htm (looking for more info)
Here are two ways you can introduce probiotics into your birds' diet. If you have a very small flock, GNC (in most shopping malls), sells a flavored liquid version of L. Acidophilus. I've used that at...
If you're unable to get her vet care, then you might want to think about becoming your own vet. I've already told some steps you can take: keep the eye clean, let her inhale oxine, and give her probiotics (none of which I have done btw) If you feel like she may need antibiotics then search...
Well after reading everything I could find so far, maybe you can try having her inhale some oxine, give her probiotics, and keep her eye clean? I'd like someone else to jump in here because I am extremely inexperienced. However, I do not believe those steps will hurt her at all.
I'm not a vet and have so far never had a sick duck. If you think you should take Motley to the vet, and you have the means, then that's what I would do. I cannot diagnose anything only show you what I'm finding as I search. I would make sure to isolate her from the rest of the flock until...
Found here:
http://merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/204000.htm
Infection with Riemerella (Pasteurella) anatipestifer is a contagious, widely distributed disease that primarily affects young ducks and turkeys. Other waterfowl, chickens, and pheasants also may be affected. The...
Check out the articles here:
http://www.shagbarkbantams.com/contents.htm
The fungal article almost seemed a good fit, but it lacked the eye problems.
Riemerella anatipestifer Infection is infectious and you said none of your other ducks are showing signs being sick?
If her breathing seems fine... check out this article on crusty duck head. Is she one of the females getting bred?
http://www.shagbarkbantams.com/saliva.htm