My mom is very similar to that except for the fact that she didn't smoke. I have been grounded for about 3 months now and have been caught 2 times since Christmas. What sucks even more is I got grounded for another month today because I accidentally slept through school. Parents can be annoying as hell but I could never not respect my mother seeing as she has given me a place to live, food, and clothing for 14 years. The best thing to do is just refuse to not smoke and be honest with them. I am open with my parents about my smoking now but it hasn't seemed to help much. But your mom smoke she will probably be understanding as long as you keep your grades up and remain respectful (or atleast fake it). Just show her that the antidrug people are full of it and she will begin to accept it.