The best calcium for chickens and the fastest absorbed is calcium citrate with vitamin D. Tums is okay until you get it. You can give the Clavamox twice a day from 125 mg to 250 mg for 7-10 days.
If her crop is squishy or puffy, massage could cause her to choke. Was the crop empty early in the morning before she ate or drank? That is the best time to judge if the crop is working. Drinking a lot is good, and could be because she is having some crop issues. The white in the poop could...
How long ago was the vet visit and the calcium? You can give calcium citrate with d3 once a day if she is still showing signs of passing egg parts. She can poop because she is not egg bound. The calcium helps muscle contraction to pass the rest of what may be inside. She could have another egg...