Well then let me have a guess...
The girl was once a victim of a ship wreck. She and some other passengers on the ship were fortunately washed up onto a shore of a deserted island in the middle of nowhere. Unfortunately, they had no food source/they ate everything/etc. Desperate, one passenger had secretly killed another passenger for his meat, and lied to the others that the meat was from an iguana he killed on the island. Naturally, the girl ate this meat with everyone else without much thought.
Eventually, they were saved, and the girl went to have a steak of iguana meat some day later, when she realised that the steak tasted nothing like what she tasted back at the island! She quickly concluded that she had ate the meat of a fellow passenger, and suicided.
