I know this question was posted 4 years ago, but I'm wondering if you ever found a solution. Our 4 year old son deals with what sounds like an identical problem. We've had swallow tests done and tried allergy medicine and nothing has been helpful so far. We are now considering therapy to make sure he's chewing properly. I would love to hear about your journey with your daughter and what was helpful and not helpful. Thank you!
Try keeping a food diary and noting what she eats and whether the symptoms increase or decrease. A lot of what you're saying may suggest that she may actually be exhibiting symptoms of a food intolerance issue.
The outcome may not be clear-cut, but the common food groups can include dairy (of any kind), gluten (wheat, rye, barley and in some cases oats), some fruits, corn, and in some persons, meat. But it could be almost anything IF it is due to food, so you're going to have to track things for awhile. If you think you've found a 'culprit' take all forms of that food out of her diet and see what happens.