I found a flaw in my background fabric and used a flower fussy cut from fabric and applied with Wonderunder to cover the flaw. It worked well since I could do a machine buttonhole stitch around the patch before sandwiching. Since yours is already sandwiched, I would use an appliqué that you could hand sew down over the boo boo. Find some cute little motifs that you could write a little message on and sew it on. Label don't have to be in the corner of a quilt.