Does she have any other concerning behaviors? Is she off balance at any other times? How severe is it? Is she just a little shaky or is she falling flat on her face?
If it's just her getting off balance when she shakes herself or goes down the stairs then I wouldn't worry. Chickens are...
something like this happened with my rabbits. one of my rabbits unexpectedly became paralyzed overnight from the waist down. as you may guess her butt got quite dirty from not being able to clean herself properly. she started to stink. she had flies and ants in her cage. my brother caught a...
i had an Americana chick once... i named her cutie-pie. couple weeks later she started crowing. turns out its a girl! we changed it's name to super-supper.:lau:gig
it was really freaky watching them eat that thing. it was a pretty large mouse and you could see the chicken's neck kinda bulge as it went down :sick! GROSS!!!!!!
the website "the chickenchick.com" has a very good method for introducing new members she calls it "the playpen method" look it up, it is a good idea for when you start introducing new members.
i don't know if it will harm your ducks. are otter sightings common where you live? if it starts hurting your ducks you might want to catch it and move it out of your pond. otters do have sharp teeth so be careful if you beside to do it. you may need to call animal control in order to help...