User blog comment:Miskos3/Episode 275: Fairy Tail Zerø: An Eternal Adventure, Review/@comment-24277053-20160416023702/@comment-7418318-20160416075857

Let's see: Miko is about 6 years by looks. Zero happened 108 years before the current point of the story...

So 114. That's not an "old lady" anymore and she certainly wouldn't work in a bakery anymore. Hell even a daughter or son would already be old enough to go into retirement, but if she had grand-children they could work the bakery... assuming it survived more than a century near Fairy Tail and most especially Cube's attack.