The only way I have seen Minky mixed with cotton in quilt tops is as an applique. One lady in our Linus group pieces cotton quilts and then to add texture, she appliques Minky, fleece, and other textured non-cotton fabric circles positioned here and there on the top. In your case, since matching seams might be a problem, the appliques could be placed right over a bad seam match and nobody would be the wiser. It is true that the little children love the textures on their quilts!