Just a thought, but since wonderland is a part of all this, what if "HER" is Alice? Of course that would make her from this world and she'd have to be very old if her original "adventure" took place before the book was written. But then the timelines don't make a lot of sense anyway. I mean I got the impression that a not insignificant amount of time passed in the enchanted forest between when Bae left and the curse was cast, show why isn't Bae a lot older than he is? Perhaps time does run at the same speed in all worlds?
On the other hand "HER" could be Dorothy. I mean it's just a matter of time until Oz gets in on the action, no?