... why would Runa know how often elf villages burn down, or anything about the elves of this world? That seems like a weird comment from an isekai protagonist.
Do elf villages burn down a lot in other Isekai/Japanese Fantasy stories? Remember, when Runa encountered the goblins and ogre in chapter 6, the first thing she remarked on was that they "do horrible things to women", much to the confusion of the other characters, so I think she's just running her mouth based on common genre cliches and assuming that this world works that way.