Interesting theory. So you're saying she was "deleted" out of another timeline so she snapped into this one with partial memories still attached of her old timeline. However, I wonder why it occurred exactly as she slept? It would make sense to me if somehow when she slept, her conscious mind got swapped with an alternate version of herself. Would it then be possible in her timeline, the version of her was 'plucked' out of this timeline and dropped into another? This is all speculative, but a lot of this would likely make some good stories or movies.