I have something very interesting to report. Let me know if anybody else has seen this!
I started a new game. I went to blighttown immediately to get the chloranthy ring and the fire keeper soul. I did NOT kill Quelaag. I then went back to firelink, and proceeded as normal through the burg and parish. When I got to Lautrec's cage to free him, he was not there. The cage was closed, and I couldn't open it with the master key. There wasn't even a prompt.
I tried to quit/reload to fix it and nothing happened. I then just decided to kill the Gargoyles. When I got back to firelink shrine, Anastasia was dead. She dropped her normal loot. I have never seen this anywhere. If somebody can explain this, do so!