Get a big spray bottle, fill it with water. Spray the quilt with water and then stretch and iron with a warm iron. It may help to get it stretched back out.
I never never would use unknown content batting on a quilt for someone special. I would use that with a tiny practice quilt and wash it first if I wanted to use it. Be sure you tell her that she should not dry it in a dryer when you give it to her. I've copied the "quilt care" label and attach the quilts I give now. My family really didn't know how to care for them after I gave them quilts, so it's much better than to hear your quilt sparated...
Hope it works out for you, I just spent 3 days last week unquilting one because I didn't like the way it looked when I finished it. Sometimes we learn the hard way, don't we?
Hugs,
Sharon