Can you gently feel her lower abdomen to see if you can feel an egg in there? You'll want to be careful you don't break the egg in there of course, but it's important to figure out if she is eggbound because that can be life-threatening. Like lomine said, a nice long soak in some warm water should help her relax and maybe help her get the egg out if she is indeed eggbound. You can also put some petroleum jelly up into her cloaca to help with some lubrication. A shot of calcium is often the treatment for eggbound ducks at the vet's, so I would think if you gave her some extra calcium now that could also help. If memory serves, the extra calcium basically causes contractions to help the bird get the egg out more quickly. Not sure if she'd eat enough to get the same benefit as a calcium shot, but it certainly won't hurt.
If none of this works, she really needs to get to a vet asap if she is indeed eggbound. Like I said, that is a life-threatening condition.