On my goodness, she may have all the information she needs and then again she may be in a blackout mode. DO NOT BE AFRAID TO ASK HER QUESTIONS. If she is in denial she may need the push to get exactly the right kind of information and treatment she needs. If nothing else you will be getting the information that you need. No one is immune to the disease. Most will not have breast cancer, but the randomness of it creates a need for ALL women to be knowledgable. Please talk with her and encourage her to teach you.
Also it will help her to talk about the process she has been through. Maybe not now, but in the future. You are a good friend to want to support her.
Perfume and incense bring joy to the heart, and the pleasantness of one's friend springs from his earnest counsel.