Something strange just happened... I had just turned in the Tree Hugger mission, and was picking off the nearby enemies from Aubrey's elevated position. After attacking the Pixie that spawns near the chest to the east, it came up around the regular tree that is growing near Aubrey and attacked. My shield took damage, but oddly, Aubrey fell over and went into the Treant animation of decay (sprouting mushrooms and green gaseous fumes). Before she disappeared completely, I still had the on-screen prompt to talk to her, although she didn't speak when I pressed the button.
Once I'd cleared the way, I fast traveled to Flamerock Refuge and then back to The Forest, and Aubrey was back in her spot. I'm not sure I've ever seen an NPC die before. metalheadHippie "It is not when or where men are born, but what they do that makes them brothers." (talk) 18:44, August 21, 2019 (UTC)