the first question should be whether you can afford a second child,
Good advice from The Knize there ... I'll quote just a bit, but the whole thing is worth reading.
That's the "fiscally prudent, cautious and prepared" approach, and certainly worth taking into consideration. Then again, the "financially prepared" goalposts tend to shift, and you'll always be three years and fifty grand short of where you need to be, and meanwhile time's a-tickin'.
Fools rush in where angels fear to tread ... and I'd ... well, not "rush in" foolishly, but if it's time to make babies, it's time to make babies. If you have the emotional maturity to man-up to the daily grind of parenting and financially supporting your kids for a couple decades or so, and if SWMBO is in the same boat ... no bigger regret in life than "I picked the wrong woman to raise my kids" ... and only you (not us) can answer those "ifs" ... then you have your answer.