Reading this thread, a lot of people keep asking how/when Kitty got time travel powers. I don't know. Let's check the ol' asshole and see if there's anything else up there!!
Some mutants have secondary mutations like diamond skin and telepathic powers. Maybe, in the movie universe, Kitty is one such mutant. Not good enough? Well, maybe she encountered some mutant with the ability to transfer power and she was the recipient like Johnny Storm was in the Rise of the Silver Surfer. Still not good enough? *reaches deep into asshole* Back when, it was said that Spider-Man's spider sense actually alters the future every time he used it. That's the reason for his notoriously bad luck. Time is actually against him and is trying to eliminate him. Maybe Kitty has been altering time when she phases and has learned to control/transfer her power.
Still not enough? *reaches deeeeeeep into asshole one last time* in the original version, Kitty was the one that goes back in time. Out of respect, they kept her as a major character and an integral part of the story. Just go with it. Okay?
