I too had “The Cronic Cough” for 2 years. Dr told me it was psychological, along with shoulder pain. During my flight physical at Mayo Clinic my brilliant physician listened to me, ordered a chest CT. I was in surgery within 48 hours! A brilliant team lead by a thorasic surgeon removed a 3cm tumor and my upper left lung lobe. I had lung cancer. I Never Never smoked !
Lung cancer take 422 lives each day. With proper diagnosis and proper treatment at a larger medical facility, away from my small town, I am grateful to be a 12 year lung cancer survivor.
Do you know lung cancer is the #1 cancer Killer? In this Centry 1 Billion people will die with lung cancer.

I commend you for asking and caring for your mom!
I hope you encourage her to get a second opinion and a chest CT that may address your concerns.

The Pulmonology Medicine Department is a good place to start!
All the best,