User blog comment:Miskos3/Fairy Tail 544: You're the King, Review/@comment-4933386-20170714090726/@comment-7418318-20170714114206

Maybe Meredy leap-frogged the link through Brandish, since Dimara certainly has feelings for her.

Or maybe what Brandish told her changed her feelings toward Fairy Tail.

Either way nobody, no matter how much they might hate Fairy Tail, would want Acnologia to wipe out everything and everyone, which would naturally include themselves, so maybe the will to survive is enough common ground for Meredy to work her magic.