Smoking Question?

Karolina • Still waiting for our baby.
DH and I both smoke. We have tried a few times in the past.  We both have tried the patches but they burned our arms. I tried the lozenges and they made me sick. I can't chew gum, beacuse of my TMJ(type of lock-jaw). DH just doen't want to chew the gum. The thing is I know we should quit and I know we will for sure if I ever get that BFP. My main problem is that both of our moms smoke too. It will be easy for me to tell my mom not to smoke in my house, but my mother-in-law is a different story. She never comes to our house which I am fine with, but we live just down the road from her so we always go to her house which I am fine with too. She smokes in her house also. 
 My question is when we tell her that I am pregnant (when the time comes) how do I approach her about smoking inside around me? Do I say anything to her about it or just let her make the decision on wether or not to smoke around me while we are inside HER house?