I was going to say something about Tessalon Perles but didn’t want to give them that information.
Her cough does actually remind me of a Bronchitis cough, you can avoid it by being still and not talking but as soon as you do something or talk it starts again.
Few doctors even remember it as it is a much older drug.
Thing about Bronchitis is it does go away after a short course of amoxicillin. The cough lingers though, but it is a real deep body racking cough.
Now dry throat cough is what her’s sounds like, and is common with Hypothyroidism as is trouble swallowing. I have issues with that so am very aware of what to look for and how to treat it. That spot on her tongue may be a cough drop or a small piece of candy to keep the mouth moist. It’s an old trick to fool the mouth into thinking it needs to produce Saliva, many musicians put a pick in their mouths. Just don’t swallow it, lots of real hacking coughing then.