I'm sure your girl will heal fine. We had a little Australian spotted that was beat up far worse than that who we actually couldn't medicate at all beyond dabbing on some Blue every other day (she was the wildest duck I've ever had and treating her was more stressful than the injury). It can happen fast...we'd had that batch of ducks for about 6 months with absolutely no problems. Ratio was more like 6 to 1 than 4 to 1. We went on an over night trip & came back to find that the drakes had decided that it was spring and completely torn up that hen. Oddly, it was only THAT hen that the worst drake was interested in. When she was removed, he completely ignored the others. The instant we tried re-introducing her a few weeks later, he started at her again. He was dead that night. I don't tolerate rape in any species. And I *really* didn't want that trait to be passed down to another generation which meant that the other drakes from that same hatch also went down.