In general climbers are too emotionally retarded to have girlfriends and wives. If they do have one, temporarly, there certainly isn't going to be any communication and that rules out teaching her how to belay unless you don't mind training her for the next climber which brings me to my point. If you must climb with your sexual partner, find one that has been through a climber or two and at least one belay training session at the gym. Pack extra shit so she doesn't have to go without. And don't sneek up on her when she is going potty. They hate that.
If you think you are going to teach your non-climbing girlfriend how to belay, I have a brand new pair of EB's to sell you.