Access to grit is always good for digestion - it helps prevent crop issues, but once there is already a problem with the crop, grit won't help and could actually add to the blockage. The blockage, or bacterial growth (sour crop) needs to be cleared whilst only feeding soft foods - easily...
You mentioned a swollen foot... can you post a photo, or a few please?
Have you inspected her foot thoroughly for scratches/scrapes? Just to mention, a crop issue is most often a symptom of an underlying issue.
If you can post photos (of her poop also would be helpful) it will help people here...
If she has sour crop, she is going to need to stay hydrated. I would withhold feed - make sure she is drinking - dehydration will worsen the problem (but take the drink overnight), and check her crop in the morning and see how it is then.
If still full and squishy and her breath is smelling...