Is that flannel? Did you pre-wash it? If not, I'd wash it and dry it and see what happens. Some flannel shrinks so much it may be hardy noticeable afterward. If it doesn't look better, I personally, would probably stitch it down and call it good. Or appliqué something over it. Your friend would probably never even notice it, because who looks at the back of a quilt? But you can do something to make yourself feel better about it.