She won't know unless you tell her; I can see a difference but I personally prefer the "crunched up" kind of quilts; there are sufficient colors in the quilt to camo a bit of the shrinkage; Like many have suggested, I would wash it again on a gentle cycle and stretch out to dry - plastic bags on the dining room table would get you a good flat surface; then iron it before it is totally dry - maybe that will help reshape it some.
Sorry this happened - I would be distraught; I have a similar dilema with a quilt I made for friends, I used all cotton top and backing but the batting is a recycled mattress pad - guess I'm going to have to include care instructions.