If Dumbledore was able to escape from the predicament she put him in, he would be a genuine miracle worker. She didn't think it was possible though. Which meant that he was likely in the custody of the Death Eaters. Probably had already been dragged back to Hogsmeade and then on to Hogwarts to await his fate. Despite it still being a functional school, the castle had many uses those days. Much like the third floor corridor had been off-limits her first year, there were entire sections of the school, especially down in the dungeons, that were forbidden. Dumbledore was most likely in one of the cramped cells deep in the bowels of the castle. Or, he could be in Rabastan's custody in the Ministry of Magic. Neither location was much better than the other.