Returning to Civilization
The Goddess of Medicine is indeed correct. The Witch herself has been around for many years and because she decided to escape and become a hermit, she never knew the recent civilization updates and what happened to the plague.
"I did have a few friends who I had contact with back in the early days but soon enough, they stopped sending back letters allowing me to assume that they might have died or they have been captured and executed. It's still the same outcome, they have died so in the end, when no one else returned any message to me, I immediately knew that something must've happened that I didn't want to know and so, I remained here."