Sithera Wellspun

Sithera Wellspun is a deceased blood elf on Darkmoon Island. Her ghost is located in the eastern portion of the woods beneath the cliffs and is only visible while dead. She is one of several ghosts on the island.

Sithera openly admits she had difficulty trying to look for firewood on the island. She and Arlon Surehoof worked out of the same camp on the clifftops to the east. One day she recalls when she was out looking for firewood, she saw something in the bushes and blacked out. After she recovered, she couldn't find her way back to the camp. It's assumed at this point she died by unknown means.

Quotes

 * "I thought I saw something in the bushes nearby... Then I suppose I blacked out."
 * "I have such a hard time gathering firewood..."
 * "I was supposed to get firewood for the campsite..."
 * "When I woke up, I couldn't find my way back to the campsite..."

Speculation
If Sithera was "blacked out" after seeing something in the bushes, her death could have resulted from an ambush. Due to her inability to navigate back to camp, she either fell prey to the wilds or whomever attacked her from the bushes.

It's also possible that she was killed by Rona Greenteeth, who sells meat from a variety of humanoid races--including blood elves.