Understanding how "popular" the character of Zoe is I fully expect backlash on my first theory. But I haven't seen anything like this posted. In light of some of Shiela Kelley's comments, etc.... it hit me that Zoe has the potential to be the key to everything after all.
We know that the name Zoe means life: often a name which can be connected to mother, beginning, earth, god, etc. Without life we cease to exist. I think this is clue to the fact that Zoe will go back in time to the beginning of the cycle or circle and be there when MIB and Jacob are children. She may be on the island for many years before meeting MIB and Jacob which will allow her to figure out the island and be responsible for building the frozen donkey wheel. Her knowledge of the future, the purpose of the island, electromagnetism etc... will be essential in setting up the island's future events and in using science to turn Jacob and MIB into demi-gods.
We have already seen Zoe's obsession with finding the pockets of electromagnetism or wells. She is one of the only characters, if not the only character who actually has a true understanding on how the unique physical properties of the island work. So its only a matter of time before she is able to harness this power to intentionally or unintentionally time travel. From there she can manipulate the island's properties and inhabitants to achieve a future goal.
If this proves to be true I think there is a chance that Zoe will end up being Eve of "Adam and Eve".