There is a certain breed of man who gives up his surf sessions when he gets married and has kids. Don't be this man. It is eminently possible to be gainfully employed, to have two children, to have a wife, and to surf everyday. I speak as a father of a two-year-old son and a newborn daughter engaged in a loving marriage, and also as a self-employed person who juggles several jobs at once. But mostly, I speak as a surfer who gets in the water every day.
How do you do it? Don't marry someone who doesn't get the surfing thing, that helps. But more than that, make the priority known. The key here is for you to understand, and to clearly convey to your wife, the value that surfing has. I am a better husband and father when I've surfed.