Dear L.,
You need to get tough on this situation. Your mother-in-law needs to be told that if she wants to live in your home, she'll have to give up the cigarettes. When you have a child that is that allergic to cigarettes, even smoking outside will not help her. You can't expect your daughter to give up her health for your mother-in-law's cancerous habit. If your mother-in-law won't cooperate, tell her she is not welcome in your home. Period!
I am so highly allergic to cigarette smoke, that I've ended up in the emergency room several times when I tried to stay where people were smoking. I married a smoker. He was very good at smoking outside, but the smoke was on his clothes when he came inside. I was constantly taking medication and even went through series of desensitization shots twice. My children were also allergic to cigarette smoke. Besides what health insurance paid, we spent over $10,000 on doctor's bills their first 5 years of life. They also went through series of desensitazation treatments.
Even knowing this, when we would go to visit my inlaws, there were 3 smokers, they would all light up at the same time, but they would run a powerful exhaust fan which helped a great deal. The only problem was that it made our visits extremely cold in the winter, and the kids got colds. When they visited our home, they would smoke outside. They all still smelled like cigarettes. My inlaws are all dead now. One from cancer, one from hardening of the arteries, and the other from complications from surgery for poor circulation in her legs. Think any of this was caused by the cigarette habit? I do.
Living with and taking care of a parent is a difficult thing. My dad lived with us for almost 3 years. I was performing care 24/7 including bathing him and even wiping his butt after bowel movements. Our entire life was dedicated to his care during that time. Our outings revolved around his bowels, because he was incontinent. The situation became unbearable. Our health was affected to the point that our doctor said that dad had to be moved out of our home to where he could be cared for by others. Had my dad been a smoker, we would have not been able to take him in at all.
Research on the internet for Elder Care. Look up the local Bureau or Department of Aging. Is your father-in-law deceased? If so, were they still married at the time of his death? Your mother-in-law may be entitled to his Social Security. Was he a veteran? There are benefits to surviving spouses through the Veteran's Administration that would help pay for assisted living or nursing home. Check with the Veteran's Administration for Veteran's Non-service-related disability pension. There is also the Medicaid Program through the Social Security Administration that helps with long term care if she qualifies. Pennsylvania has a lot of programs that help care for older citizens that help keep them in your home. The costs are based on ability to pay.
Good luck and stand your ground. Every person in your household will be affected by the inclusion of this person in your home. It is not too much to ask that she places the health of those care providers before her killing habit.
Sincerely,
M.