What is the next step after a lung cancer diagnosis?

My future mother-in law has been diagnosed with lung cancer. She has only been sick a few months. I don't know if it is small cell or non-small cell though. Within two days of being hospitalized they had to place her on a vent and they have drained over a quart of fluid from her paracardium. She is breathing on her own but the tumor has blocked her airway and the tube is physically holding it open. She has now been intebated for about a month. She has also been given one treatment of chemo. I have been told that it is stage IV by a family member but I know that doctors do not categorize small cell lung cancer this way.
My question is what is the next step? Because I am not "officially" a part of this family (the wedding is next spring) doctors and nurses will not tell me details. Other family members do not want to know the bad news and don't ask. I am trying to console her husband as well as my fiance. And they do not understand what is going on. Please help me help them.