Have you checked the foot for bumblefoot?
There is a difference between sour crop and impacted crop - if she is eating properly then the crop should be large and squishy as it fills with food. To diagnose an impacted crop, withhold food and water overnight and check the crop first thing in the morning before offering food or water - it should be flat and empty. If not, then the crop is impacted. If it’s been impacted for some time, the food does not go down into the stomach to digest and ferments and turns sour and in this case you will detect a horrific odor coming from the mouth. To answer your question, yes I would separate her until you know why she’s limping; a drake won’t take pity and will try to mate her anyway, potentially injuring her further. Checking for bumblefoot is where to start, then check the crop first thing in the morning.
