How does her legs and feet look, feel? any swelling, redness. Had she been missing? also sometimes when an egg is stuck it can cause the duck not to be able to walk. Very gently check her under belly out feeling for eggs and also look at her vent to make sure it isn't pulsating.
Okay what makes you think an egg is stuck? can you see it feel it what are the symptoms? you can put her in a tub of warm water let her soak as long as the water is warm, keep it quiet and as relaxing as possible while she is in there, then when you take her out place her in a nice quiet place by herself not with any other ducks, keep food and water close by, do you have any kind of calcium supplements/ liquid or tums will even work mix some up in water to dissolve and see if you can get her to drink it. While she is soaking very gently massage her tummy in the direction of her vent , you can soak as often as you need too. you can also place her on a heating pad with a thick towel wrapped around it on the lowest setting what you want to do is provide moisture[humidity] you just don't want to over heat her.soggybottommini is right I forgot to mention lubing the vent. vaseline works.
That is good news, not what do you think it was?Great news she's back on her feet again and with the others thanks for all the help guys
If it was a stuck egg she wouldn't be fine unless she actually laid it they usually go down hill pretty fast if egg bound. Anyway glad to hear she is doing well..I honestly don't know was a weird one ! We have had bad weather here (England ) the last few days maybe it's something to doo we that only other thing I can think of is a stuck egg but when I went to the allotment this morning she was up and fine
Hens go broody when you don’t want them to… and won’t go broody when you do. 
