first time I went in there, I snuck past the room with the cauldron and all her "victims" which did not trigger her to appear in that room and talk to me correctly and when I came out of stealth she appeared but didn't talk to me, so I attacked her and killed her. Also I was sneaking in the boss fight room and she didn't appear right away until I walked in her cone of sight while she was invisible and I had to unstealth myself for it to trigger.
There may have been a flag you didn't trigger to move her into the right room, so she isn't appearing. Also going in the back door may have jacked it up. I don't know if each spawn of her is the same NPC/asset or if they have individual identifiers. If it is the same ID to designate that NPC maybe she isn't appearing because she is stuck somewhere else in the world. Try killing her in the cauldron room maybe if she is there to force her to despawn and move?
