First off, congratulations on accepting yourself and taking the steps necessary to become a woman by seeing a therapist. I've recently also come to terms with it and now I'm on my way to transition. I'm not going to lie, there is going to be tough times ahead of you and life as you know it might begin to crumble around you so be prepared for that. I suggest, in a little while, to come out to your wife since the longer you wait, the harder it will be. When you do come out, invite her to see the therapist with you and to visit this website for information and a way to get herself together. She might not be on board right away but you can at least point her in the right direction for information if she's willing to read up on this. As for the children, I would come out to them ASAP since the younger they are, the easier it is for them to accept it since they are less exposed to external influences.