After a bunch of screaming, my friend and I finally beat Xibalba. After we finished Malistaire's battle, my quest finished and my quest moved to talk to Pacal Redmask, but she said her quest still was "Stop Morganthe in Xibalba". The ice zombie dino thing spawned again, and we are fighting it right now. Hopefully we don't have to do Xibalba again to continue the quest, so can anyone reply early just in case it doesn't fix it?
--Nevermind, we beat the ice dino and it fixed her quest.