Like its been already said, let nature take its course. I'd feel worse for shooting a deer or any animal knowing I wouldnt be able to recover it such as in your case. Healthy and unhealthy deer/animals are taken by predators every day so its gonna happen eventually. If this is bothering you, I think putting her down and not even trying to recover her due to the terrain and such would bother you far more cause you "just left a kill" in the woods. You did the right thing by letting her walk.