I'm sorry for what your friend is going through.
Just my opinion, but you may want to consider something other than a breast cancer theme. As a cancer survivor, cancer and its treatment takes over your life. I can't think of a single area of my life, from food to hobbies to work to bathroom habits. The one thing that I longed for most during 8 months of chemo and radiation was NORMAL. My vote is for something in bright, happy colors if you don't know her favorites.