User blog comment:TheCarrotSaysYumYum/Fairy Tail Chapter 416 (Tartarus Arc - Last Chapter) Review/@comment-1839664-20150121165236/@comment-7418318-20150124113513

Remember that nobody except for Gray and maybe Jellal and Meredy knows that she's an old woman now. They were probably looking for someone in their late 20ies or 30ies (or however old she is), not a 90 year old grandmother look-a-like.

Not even Jellal and Meredy, who've been travelling with her for years, recognized her when she was standing right in front of them and gave them the letter (maybe they figured it out after she was gone though), so I doubt that the Tartarus members would.