I do not believe your bird has or has mites. I have never seen a lovebird with mites in all of my many many years practicing exclusively on birds.
Lovebirds have something called polyfolliculitis. This is a genetic problem and cannot be cured. It can be attenuated with medications. I don?t know that that is what your bird has but it is a possibility.
Another possibility is allergies. Maybe a food allergy or a contact allergy. What do you feed your bird? Has the diet changed or have you changed brands of food. Some vitamin mixes in seeds can cause this allergic response. Also some brands of pellets particularly the colored and sweet ones can also do this.
( Harrison's pellets are organic and what I recommend you feed your bird.)
Since she is rubbing her face, there may be something inside her mouth that is causing irritation.
You need a veterinarian willing and knowledgeable enough to investigate these things more thoroughly. Often times a good history from the owner will tell you what is going on. Maybe this veterinarian has not asked all of the right questions.
It may be a good idea to do some blood work to rule out infections. A protein electrophoresis can also help narrow down the possibilities. Even a skin biopsy may be necessary at some point if a diagnosis cannot be determined other ways.
