Lyn, I'm so very sorry to hear that your Mom has all this discomfort! Of course, as you and she know that the smoking makes this worse. I smoked for many years even with my asthma, so I didn't make my situation any better myself. Though, I did quit several years ago successfully and plan to keep it that way.
It's so hard and very sad when it's your parents though and you have to watch the downhill decline to their health. I wish I could offer you more suggestions, but it sure sounds like you're on the right path, just being there for her and offering what you are able and she's able to tolerate.
Please, Lyn, just give me a holler if there's anything that I can do to help? I've always got a good shoulder and an ear for listening.
Best Wishes to you and your Mom.
Big Hugs, Teri