Carter, Jay has a long road in front of her. She will need your susport and understanding. She will have good days and bad days. Don't show her your downside. Watch the tone of your voice. Always keep a smile on your face. You have to be her cheerleader. She will pick up on the little things you do. It's going to be tough. But the end result will be well worth it.
This is what I had to do when my first wife went through cancer. Hang in there buddy, we all, are behind you. If you need to talk, pm me your number and we'll go from there.