Her foot pads look fairly healthy in the pictures excluding the cut on the medial toe - I really don't think you would need to bandage the feet, but if you feel it may be beneficial by providing her feet with some cushioning, you can certainly try.
To be general, if we're not dealing with an inflammatory foot disorder (exp, bumblefoot) duck leg problems are going to be most often correlated with soft tissue trauma, such as sprains, or strains. If the males are being hard on the female, the overall best treatment would be reducing the amount of mating going on since a large amount of these leg injuries can be due to over-mating from the males.
NSAIDs (non-steroidal anti-inflammatory drugs) such as aspirin, or if available from a vet carprofen, or meloxicam will work well at reducing any inflammation. If using aspirin, you can dose the duck at 5 milligrams per kilogram - continue that once a day until you see improvement. Furthermore, you can practice hydrotherapy and let the duck bathe in cool Epsom saltwater, not allowing her to drink the water.