It does sound like she might have a respiratory infection, but hard to know if it is coryza, or one of the others. Usually, coryza causes thick yellow nasal secretions, swelling and gunky eyes, coughing, and rattles. There can be some other causes of a bad odor coming from the beak, such as canker or sour crop. Can you look inside her beak, cheeks, and throat for any yellow to white material? Also feel of her crop to see if it is full and hard, doughy, or puffy? The best time to check the crop is when it should be empty in early morning before they eat or drink.
If you can get some antibiotic from a vet to treat the respiratory symptoms, it may be helpful. Probiotics can be helpful for helping her fight off illness. If you see any material inside her beak, let us know. Canker is a contagious disease carried by pigeons. It and wet fowl pox inside the mouth and throat can look similar.
Permethrin is very good to treat mites, and needs to be applied at 5-7 day intervals at least 2-3 times to kill the mites, and newly hatched eggs.