Great advice here, Ren.
I remember when I was a smoker, I didn't want to hear someone trying to tell me how bad smoking was and why I should quit. Now, when I'm in the presence of someone who smokes, I really want to tell them how much better their lives would be without cigarettes but I know that it probably will do nothing but irritate the smoker.
Keep your quit going strong and try to be an example to her. Hopefully you will inspire her to stop with the social smoking.
You can't control what she does. You can control your actions, though, so keep your quit going strong. At over 2 months smoke free, you are seeing how much better life is as a non-smoker and I hope this will help her realize that there is no need for cigarettes in her life either.