it's probably for the best. human beings are a blight on the earth. all other living species suffer the more we procreate. for me, best case scenario --BEST-- of you and your wife having another kid, is the kid grows up to be a really beautiful woman. but that's not gonna be for another 20 years. and then we're gonna have an age gap of 30 years, so the chances of a normal relationship is pretty much out of the question; she'd have to be a stripper.
and look, i know you're not a miracle worker, i know you can't guarantee that you can bring a hot stripper daughter into this world, so just forget it. buy a boat or go on a nice vacation once a year instead.