I am a breast cancer survivor and would have loved a quilt like this. Your friend is going to be so thrilled. I would enjoy a small border then a larger pink border as that is the color for breast cancer. Just my choice. I would want it long enough to cover my feet and come up under my arms while lying on sofa.
Did anyone give her a breast cancer pillow? A heart shape pillow about 9" given to me was so useful under the seat belt in the car. 2 little 5x7 pillows were so helpful under my arm for about a year while I healed. Would be nice to coordinate with the quilt. She will love whatever you decide because it is made with love. What a great friend you are who happens to be her cousin!!