What are you feeding?
Can you get some photos of the poop?
How old is she?
I would treat for Coccidiosis if you've only had them 5 weeks and likely I would treat for crop issues as well.
You can find Corid at Tractor Supply in the cattle section.
Dosage for Liquid Corid is 2 teaspoons per gallon of water and Corid Powder dosage is 1 1/2 teaspoon per gallon of water. Give to all the new birds as the only source of drinking water for 5-7 days.
Check the crop again - read the article below. I would probably start by treat as sour crop. Coccidiosis can also cause some crop issues if the intestines are inflamed, so if she were mine - I would treat for both.
I might change my mind once photos arrive - but new birds, crop issues, coccidia...these come to mind right off the bat.