User blog comment:Miskos3/Fairy Tail Chapter 490: Fairy Tail Zerø, Review/@comment-5268982-20160622085020/@comment-124.104.239.150-20160623162150

I think the reason that she was able to know exactly where to send Zeref was because she enchanted the land itself. Perhaps she was able to "connect" with Fiore and thus were able to do what she needed to do like detect the exact location of Mavis.