As I got back from Blighttown to Firelink Shrine, I noticed the firekeeper woman who doesn't speak wasn't there and after examining it said she was dead. I had a firekeeper soul for her as well. I looked on the wiki and all it says is that when the player themselves kill them then they don't return so you can't relight the fire. I never touched her though? Just wondering what the problem is as Firelink Shrine is way too helpful a fire to lose.