She was picking around the bottom of her kennel this morning so I tried the kale with her again. She had trouble swallowing a larger piece (about the size of a nickel) but managed to swallow a few smaller (pinky fingernail-sized) pieces! And she ate them with great gusto. I tried a handful of peas and corn and she DEVOURED it!
Today is a beautiful day, warmer than it has been (50 ass opposed to 20s) so I really wanted to get her back outside with the others so they can get back their group dynamics, as I've noticed the remaining female is getting pretty pushy (the injured duck has always been boss). I'm keeping an eye on her as I will be outside enjoying the weather today.
She was a bit wary when I first put her out, as I expected, but no one was hurting her, and it's warm enough to not be worried about the cold. I fed them all some corn and peas but she mostly deferred to the others. Then I poured some water into a shallow basin and they were all excited to bathe (and there was some enthusiastic copulation).
I will watch to see how she eats today. They are all still coming in at night still, until we can predator-proof their stall, but we may give her a feeding when she comes in tonight just to make sure. And I'll check again in the morning to make sure she is eating well on her own.
So glad she's doing better!