My mother passed away from ovarian cancer several years ago. She also was very cold but could not tolerate anything heavy. Your quilt top is beautiful and cherry, I would purchase some nice polar fleece then use it as the backing and batting so your quilt will remain light but nice and snuglley warm. I also had made a quilt using wool batting that was very light weight and warm in the winter yet cool in the summer she used that as well. Prayers for you and your friend she needs your friendship now more than ever since so many people tend to pull away from friends who are ill.