Can you post a picture of her beak? I'm not clear on your last comment on her feed.....
How long ago was the beak injured? Many times they adapt well with a little help. Making a thick mash (like oatmeal) of feed and water helps them to scoop it up with the bottom beak. Using feeding and watering dishes that are deeper can also help, and raising them up to shoulder height can help them to scoop. There was a thread on her somewhere about a bird that learned to drink by submerging her head entirely. Pecking things at ground level can be very hard or impossible for them depending on the beak. If she is losing weight due to not being able to feed well, then you may need to hand feed her until she gets it figured out and can maintain weight. I would start weighing her regularly and monitor her weight, they can lose a lot of weight before it becomes visually obvious.