Without being able to see it, we can only guess. If she had a full crop when she passed, then it could have been crop contents that came back up when she died, that can happen. Coming from the beak and nares would be not uncommon, can't say if it was coming from the eyes, or had just gotten in there during dieing, sometimes they thrash around as they pass. A necropsy is often the only way to know for sure what happened. And they are very good at hiding illness, so it's possible that there really was something going on that went unnoticed because she was hiding it so well.