Originally Posted by The Joker
3 years or a few months, it's the same continuity goof. He was a little crying baby in Begins, and in TDK he was about 8 years old.
The baby brings me so much trouble with my timeline. I always thought that the baby was Gordon's daughter, I didn't pay much attention to it in Begins, and since in TDK we only see little glimpses of her, seemed fair enough. But according to IMDB the girl who portrayed Gordon's daughter (Hanna Gunn) was six or seven years at the time of the filming. And seeing the scene again, it is clearly older. So it doesn't add up.
Since it's the most notorious continuity issue in the films. I'm going out on a limb and say that the Gordon's were babysitting.