My only comment would be not to try to hand-quilt 2 layers of W&N...ask me how I know. Since you're doing it on a machine that shouldn't be a problem. Especially since W&N is kind of 'sticky' anyhow I don't think you'd have much of a shifting issue as long as it's reasonably well basted. That being said, I agree the one layer of W&N is pretty heavy and warm all on it's own but I understand complying with the wishes of your children.