Let me just preface this by saying that I think kids are great (and this is not taking into consideration the other benefits of having kids, like happiness and sense of purpose and things like that), but if your goal is not just to get up early for the sake of getting up early but to get up early in order to get things done, it seems like having a kid would not necessarily be a net benefit time-wise as the reason you need to get up early with a kid is to spend time taking care of them. Of course, I don't think having kids ever stopped anyone from taking over the world, so this may be an invalid point.