When we observe light that has taken 13 billion years for it to reach us we're looking at it as it was 13 billion years ago. As the universe has been expanding and the speed at which the space between objects increases, what was 13 billion light years away 13 billion years ago is now 46 billion light years away. Hope that actually makes sense.
In short, we see things were they were when they were emitted, not where they are now billions of years later
