User blog comment:IamJakuhoRaikoben/Chapter 451: Fairy Heart, Review./@comment-5268982-20150907084025/@comment-7418318-20150907193515

I doubt Zeira was buried in Mavis gave. At least in the MS translation Mavis literally called it an "empty grave" and not a surrogate grave.

Besides I doubt that there would be all that much left of Zeira 18 or so years after her death.

If Mavis did not bury her back when she died, there is certainly nothing left of Zeira save for scattered bones dragged all over the place by animals. And if Mavis did mange to bury her with her six-year-old body, then they'd have to find that old grave, exhume the remains (which ought to be only bones) then move them in the other grave... It'd be hard enough to fool the rest of the guild into believing that Mavis is buried there without a body, but a more than half decayed skelleton would make it even harder.