To be honest, I also had the urge to help her, as I didn't think that NPCs were merely the system's automatically generated moving objects, but dwellers living in this world. If this was in a normal quest progression, helping that girl, accompanying her, and as the story progressed until the end, hearing her laugh from behind, "Uhahahaha, you fool―", would still be amusing. However, we were not in the situation to take that unnecessary risk now.