You’re totally right to worry — no one wants to be rude in this situation. After all, the act of politely asking someone to stop smoking is known to cause lung cancer to those around you.
OH WAIT.
It is not a big deal to kindly request that your friend quit lighting up in your presence. Which is a shame, because you really need to put this chick in her place. SO. You ever see the terrible George Clooney Batman movie? The one with Poison Uma, and Alicia Silverstonecoldcareer? You need to get the freeze gun the Gov. Schwarzenegger used in that movie and train it on your friend the next time she even reaches for her smokes. She’ll get the message.
If she doesn’t, Commissioner Gordon has 11 minutes to thaw her out.