In each game I have played so far, I have always had 4 offspring. And I seem to notice the AI players getting the same.
Also, one of the bugs mentioned before was that the AI players seem to get married on the first turn and start cranking kids out right away, while the player can't do that.
Since offspring need a good while before they become playable, this would be a significant edge, if the AI was actually working correctly (which it mostly isn't).