Is she able to poop? What's that like?
Is the crop hard, soft, squishy, doughy, fluid or air filled?
I've never used baking soda for a crop issue so can't say whether that will work or not.
Try to determine which "type" of crop issue that she has, each one is treated slightly different.
Both articles are very good, one is short and sweet, the other is more detailed. Do keep in mind that sometimes there is something else going on that's causing the crop not to empty properly- whether it's a blockage/impaction (can be in the gizzard or intestines too) or inflammation from Coccidiosis, worms or infection.
https://www.backyardchickens.com/ar...w-to-know-which-one-youre-dealing-with.73607/
http://www.backyardchickens.com/a/impacted-slow-and-sour-crops-prevention-and-treatments
