my girlfriend never smoked a fag, never drank alcohol (she has tried wine and stuff but never got drunk per say), and she has no problem with me smoking pot with her. I obviously don't smoke in a closed room near her, always outside or in a very open place if I'm close.
Use Axe afterwards, and a toothbrush obligatory.
I would also rather have her smoke pot than get drunk every weekend. I mean, who wouldn't?