[gemy]

I know this will make more work for you, but what I might do, is leash her and walk her out in the back yard. Also try to get her focussed on you by treats and game playing, bit by bit. Have you walked her outside yet? Beyond the yard, down the street n back again? The other idea is, there might be some sort of animal that is marking outside the fence, cats are notorious for this. If you walk with her outside the fence line see if she gets real interested in a particular spot or three outside your fence line.