GoodHousekeeping Magazine, Toilet Paper Manufacturers and Hotels say over, so the overwhelming consensus from those that appear to matter is over. Why not compromise? You get it your way one roll; she gets it her way one roll. Or, you can ditch the horizontal configuration and go to a vertical one, which solves your problem.
It doesn't however, solve your bigger problem; why are you arguing with your GF on this or really any other matter. If mama ain't happy; nobody's happy. Plus, you just may want to see her naked again. Frequently. She's the relationship equivalent of a Wookie. Let the Wookie win.
Or maybe you could talk her into going both ways, which is win/win. Trust me.