I would be VERY cautious of using anything "antibiotic" at her age. The side effects may be worse than her condition. The first few days to a week will be critical, so be prepared.
I would try electrolytes before anything...
Well...there are TONS of pix on this forum, but not all in one place. Just start the browsing and look for the word "pictures" or "pix"in the post.
If you are looking for specific duck pictures, please post that...
I had mallards, and the ONLY way I could tell sex was when they were about 3 months old.
Up till then they all look like females. Keep a watch on the top of the heads. The males will start to show a greenish tint (in the sunlight)...
New quarters in the works! If you have read my other posts, I recommended a dog containment pen (flexible and portable). Since spring is here, you should really start looking into their "optimal containment" when the mature...
A wading pool will be ok for a while, but the ducks will be getting big (as FAST). They will be able to hop out.
Since it is spring now, you may want to try a portable foldable dog pen. You can use it indoors or...