Dry cough

My mom has had asthma for over 20 years. For the past month or so, she has this persistent dry cough. She has absolutely no history of smoking or anything like that, but it worries me because what she does all day is cough two times (it only lasts about 5 seconds). It doesn't leave her out of breath and she doesn't have chest pain, and she isn't fatigued either. She is very energized throughout the day and works hard at her job. She got laid off at her job 5 years ago, and she was sitting around the house all day with nothing to do, and ended up gaining a bit of weight and being diagnosed with borderline type 2 diabetes. She finally got a job a little bit over a year ago and has lost a little bit over 30 pounds in one year. Her job requires her to do a lot of work (she works in a deli so she is constantly running around the store, cleaning, lifting, etc.) and has been watching what she's eating. I am so worried though because I read online that if you have a history with recent weight loss and you are experiencing a dry cough, it could be lung cancer. Another thing I am worried about is that she gets these rashes (they aren't anything big, but she had the same type of rashes the at the same time last year.. so I am assuming that it is a seasonal thing? SHe has dry skin and her rashes come after she touches dusty things) but I read online that skin rashes can be a symptom of lung cancer as well. Am I being a hypochondriac right now or is this something to worry about? I don't think that her weight loss is anything "unexplained/unexpected" because it happened right after she started going back to work. However, with the rashes and coughing, I am a bit worried. Also, she told me that she stopped taking her inhaler properly (she skips doses in the morning and takes the night time ones in order to make her medicine last longer because she currently doesn't have health insurance and doesn't want to pay the $150 for the inhaler each month). She said that she has been skipping doses for the past couple of months. It still makes me nervous though. Please help!!
Thanks.