Also give her vent a good checking over (you ptobably have already, she may have internal laying issues? )
Also give her feet a good once over. How old is she?
Sorry about your sweet girl!
A couple of things to consider: has she been wormed lately? Has she had a good dose of vitamins? I would start there. Safeguard horse wormer is my first 'go to' when I notice anything off. Your girl's natural resistance to parasites might be compromised due to molt...