Madam Bones had sequestered herself into a room that contained a variety of furniture and implements to protect herself. Now, one would think the best thing to do was to teleport right in on her, but since she was being attacked, it was better to appear outside of the manor. This would allow me to pick off some of the forces and get a better idea of the battlefield. If Voldemort was there, then I would need to single him out and get him away from Madam Bones. 