At this time, we do not have any formal screening processes for lung cancer. This includes both people who smoke and people who are exposed to second hand smoke. The reasons for this are complex. In addition, methods of screening for lung cancer may improve in the future to the point where there will be routine screening for smokers, but we are not there yet. Right now, the only way to detect a lung cancer effectively would be to do annual chest x-rays, or chest CAT scans on everyone that is susceptible to lung cancer. Most studies have shown that doing this routinely does not save lives. All it does is expose people to extra cancer causing radiation from these x-rays and CAT scans.
With that said, your daughter should not be exposed to your wife's smoking. Not only does this increase her chances of lung cancer down the road, but it will make your child's asthma
worse. I cannot stress this point enough.
I suggest that you schedule an appointment for your daughter to see her pediatrician
. Your wife should attend this appointment. Ask the doctor
to provide advice on how to best control her asthma. This will include having your wife smoke outside and never in the car with your child. I hope that answer helped.