Enla was essentially kicked out of service with the Wood Wailers due to her sudden onset of blindness and the pervading tensions between perceived tribal Keepers of the Moon and Gridanians as a whole. (Basically it's complicated.) She's only beholdened to her mercenary group in the loosest sense and unless they ask her to return she has pretty much free rein to do as she pleases, within reason. Even then, if her mercenary company tried to restrict her movements to Ul'dah where they are stationed she'd rip her contract apart and not look back for a second.
It also helps that Eorzea for as large as it feels it should be, isn't that big at all. There's an NPC in Horizon that states that they made the trip from Gridania to that outpost in a day, though it clearly almost killed both them and their chocobo due to exhaustion. Factor in airship travel which has probably become less restrictive in the years since the story started and I wouldn't be surprised if it really did just take a day to get from point a to point b. Which means that even those who work for strict groups could in theory use their days off to go wherever they honestly pleased without too many repercussions. Point is, if you really -really- needed to fish for an explanation there's almost always one to be had even if you want to play the idea straight and mainly keep your character in the general area of where their job has influence.
It also helps that Eorzea for as large as it feels it should be, isn't that big at all. There's an NPC in Horizon that states that they made the trip from Gridania to that outpost in a day, though it clearly almost killed both them and their chocobo due to exhaustion. Factor in airship travel which has probably become less restrictive in the years since the story started and I wouldn't be surprised if it really did just take a day to get from point a to point b. Which means that even those who work for strict groups could in theory use their days off to go wherever they honestly pleased without too many repercussions. Point is, if you really -really- needed to fish for an explanation there's almost always one to be had even if you want to play the idea straight and mainly keep your character in the general area of where their job has influence.