That's the point. You don't wait until he is ready to cope. You help to transition him into coping. Read as much as you can about children and D and how best to take care of it.
Trust me. Don't wait until it's too late. You don't want him resenting his mother and you.
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.