I have a mallard with a broken leg that feeds under my bird feeder. She has a male that is usually with her. I hate to have her picked up by wildlife rehab if she will adapt and survive. If I leave her is there better food I should get for her? I would do anything I could to help her

Does she put any weight on the leg or does she drag it around? Wildlife can survive some pretty bad injuries. If she's putting some weight on the leg she might make it (though she'll be at a disadvantage against predators). If the leg is badly damaged it could impact her ability to fly, which would make it very hard for her to migrate. If you want to provide food other than birdseed I would recommend purchasing a commercially prepared duck food. You can buy bags at farm supply stores. If you have other questions please feel free to e-mail me. Good luck!