Dear S.,
Divorce is Hell. No one likes it. When I got divorced, it devestated my friends and family. It's terribly sad and it is scary too. My friends kind of freaked out because if I was getting divorced, what about them? It seemed to have shaken all the marriages up a bit as everyone started reflecting upon their own relationships.
I suggest you drop thinking about and talking about her divorce! You never know what goes on behind closed doors. If your friend is as you say she is, it should be easy to drop her as a friend. Who needs such people in our lives? But, if there is a possibility that something else is happening that you are unaware of, then you should rethink your position.
I am divorced and I can tell you from experience that there are two sides to every story. My ex would say I took him to the cleaners and that simply is not true. Others would say he got off easy and that simply is not true. The truth lies somewhere in between and only My ex and I really know.
Finally, if you can't listen to your friend without judgement and criticism, then just tell her you can't listen to her if she's going to talk about the divorce or her affair. That's fair. You don't need any cheap drama in your life. You probably have enough going on in your life as a working parent!
Good luck, remain as grateful for your family as you obviously are, and take care of yourself!
S.