STATISTICS ARE IRRELEVANT!!!
Tell yourself that, in no uncertain terms! Otherwise, you'll end up talking about numbers and statistical probabilities until you are both blue in the face. She isn't stupid, and probably isn't ignorant, so just hammering away with facts will be very frustrating for you and aggravating for her.
She is likely suffering from liberallogic, which is largely impervious to the facts. Feeling states are largely the cause of this state of mind, and the approach to dealing with it also involves manipulation of feelings.
Here's one fact, however: if she is a victim or a rape or murder, she will be a 100% victim, and the "retrospective likelihood" will have been 100% in her case as well. Those are the only statistics that matter.
If she "feels" she is safe where she is, fine. So be it. Does she wear seat belts? If so, ask her to tell you which streets are the "safe ones" so she can make a list of the places where seal belts are unnessessary. Ask her if she would "feel safe" removing her belts on these streets. No? Why not?
Her "feeling safe" in her appt. is no excuse for making believe nothing bad can ever happen, and asking you to disarm yourself because carrying makes others "feel" uncomfortable" is akin to her asking people riding in her car to not wear selt belts because "these roads are safe" and belts therefore make her "feel uncomfortable".
You need to put your foot down here, sir. If you care about your safety and hers, don't get wrapped up in useless, unwinnable arguments about stats.