Is she concerned that you'd be attacked by a registered sex offender?
Hah, beat me to it.
But as to your issue, I have the same issue with my own lady. She could care less if I carry while out and about solo, but I tend to get the "evil eye" when I do so while we are together.
She actually refuses to let me in her car armed - meaning I drive everywhere.
My solution was to start pocket carrying and just not tell her. That worked pretty well up until she got pulled over for rolling a stop sign and I leaned over her to inform the officer that I was armed (OH requires notification). He was appreciative (and even let her slide on the ticket) - she