But that would depend on other factors not just the probability of lung cancer. That depends on what her motivation is to smoke (relaxation, social partnerships, reducing her anxiety, stress management). In that case the temporary benefit gained from smoking may outweigh the Bayesian probability of her getting lung cancer which will take 20-30 to take hold (most likely) rather than using other means to mitigate her very present problems. If she is deciding to smoke or not based solely on the probability of getting lung cancer and her anxiety level about that the rational brain usually chooses to do things that reduce risk rather than increase it and if she is looking to reduce the anxiety level she should choose not to smoke because the chances of lung cancer derived from smoking go down. However, she could also use nicotine as a way to cope with her stress or anxiety which may provide a much better present relief and mitigate any anxiety she has about developing lung cancer in the future.
But that would depend on other factors not just the probability of lung cancer. That depends on what her motivation is to smoke (relaxation, social partnerships, reducing her anxiety, stress management). In that case the temporary benefit gained from smoking may outweigh the Bayesian probability of her getting lung cancer which will take 20-30 to take hold (most likely) rather than using other means to mitigate her very present problems. If she is deciding to smoke or not based solely on the probability of getting lung cancer and her anxiety level about that the rational brain usually chooses to do things that reduce risk rather than increase it and if she is looking to reduce the anxiety level she should choose not to smoke because the chances of lung cancer derived from smoking go down. However, she could also use nicotine as a way to cope with her stress or anxiety which may provide a much better present relief and mitigate any anxiety she has about developing lung cancer in the future.