she's clearly the one who made it home early, since NEM takes place in 2379 and Future!Admiral Janeway didn't make it home until 2394.
Crap. Well you just killed Christmas.
You forget STXI's mind-meld flashback to prime-2387. And Spock and Nero's warp ships.
That's true. However, back to what I said about personal continuity and canon not really mattering unless you're producing the next Trek film... I don't consider STXI to be part of the continuity of my Star Trek. Yeah, it's canon, in that it's part of the officially sanctioned universe and must be respected by those producing future works. But I choose to discount it and presume that ALL of it, even the parts supposedly in the "prime" universe, represent a parallel or alternate reality totally separate from the one that came before.