User blog comment:FairyRaven/Fairy Tail Chapter 470: Hybrid Theory, Review and Commentary/@comment-5303512-20160127022735/@comment-5303512-20160127050445

Well Layla did die in the year X777 same year when the Dragons and Dragon Slayers came from the past, and this was shown at the end of the Phantom Lord arc, so obviously Hiro had all that time to make sure Lucy's family was somewhat connected to Zeref and possibly Natsu.