Does she have an enlarged lower belly down between her legs compared to others? You can see the air filling the air passages around her beak. It is hard to know if she has a physical condition, or a respiratory disease. Mold can cause aspergillosis, a fungal respiratory infection, and it can spread through the air sacs. It could be another type of respiratory disease, viral or bacterial, or she could have a heart problem. If her belly is bloated, she might have ascites (water belly) which can cause labored breathing. I would look inside her beak and throat for any mucus or yellow gunk that might cause an obstruction. Molt is a stressful time when sickness may show up.