I do find it kind of odd how almost all drug advocates on the internet love to tell people they're "closed-minded" or "ignorant" or a whole host of other terms whenever evidence (anecdotal or otherwise) or opinions are presented that they dislike or do not agree with. Make no mistake, I am not saying that ALL drug advocates do this, as I know one personally who is one of the least patronizing people I know, just that I seem to find many who do.
On topic: This really depends on whether or not it bugs you, and what you judge her responsibility level to be. Personally, the smell of pot gives me migraines (as with the smell of many other things), and I find the behavior of intoxicated people to be annoying and moronic. There are also short and long term health risks to the use of cannabis, some of which are quite serious (an example of short term being impairment of judgement, as well as hand-eye co-ordination; an example of long term being lung cancer and possible psychosis.) which many people do not know about, and which many people will never admit are real.
If you can deal with that, then it comes to her responsibility level. Do you think that she could restrain herself from pot for an extended period of time if she had to for your sake? Do you think she would ever walk into your workplace high? If the answer to those or any of the questions they inspire in your mind is yes, then you should probably reconsider the relationship, or at least talk to her about it, and tell her about your fears. If she is a mature and responsible individual, she will understand. If not, well, she may break up with you.
On a closing note, I hope the relationship works out, because if you are letting this bug you this much, you obviously care about her. As someone said before, a relationship can work through anything if both sides put enough work into it.
