The thing is, I believe there's a really big chance that Lori just talked freely in front of both Tylee and JJ about that stuff. JJ probably didn't care, but Tylee probably did catch some weird stuff. I think it's very much possible that Tylee knew what would happen to "zombies". I'm not sure if they ever talked about Charles being a "zombie", but she knew he died and how he died. It wouldn't surprise me either if Lori talked and talked and talked so much trash about her father, maybe even saying he was a zombie too. Her father was also dead. So... her reaction really does break my heart because there's a big chance she was aware to some extent about what was going on.