As I interpret from the information that has been released so far, Kiri is anything but ordinary, possibly since birth. My theory is that she is the daughter of Grace's avatar, with Eywa having played the main role in the conception. Possibly Eywa had Grace reincarnated in this way. If that is the case, it would make sense Kiri has a lot of influence on the Pandoran environment as she would be in a sense Eywa's own daughter also, who could have been given a special purpose or role to fulfil in bringing back balance, like "the chosen one". You could take this a step further and say that if Eywa is a god, then Kiri is a demi-god.
Though I think it is interesting on a certain level, I don't know if I like this whole god and demi-god business from an overall story perspective. I still have to get used to hearing Weaver's voice and associate it with this character; she just doesn't sound like a teenager in my ears.
And btw, I think that article is way off with the theory that the real Grace will be resurrected; For all intents and purposes she has already been as good as reincarnated with Weaver playing Kiri. Do we really need Weaver playing 2 extraordinary characters in the same movie? It would go a bit over the edge if you ask me. However, I would be perfectly fine with Weaver as Grace in flashbacks or video logs, because that would be somewhat grounded.
