There really isn't a single place where quilt labels must or should go. I put mine in the bottom right corner on the back. You can either machine stitch it prior to quilting or hand stitch it on (only going through the backing fabric) once its been quilted. If you sew it on prior to quilting, it will probably have stitching lines going through it... but some quilters prefer not to have to hand stitch.
What a wonderful gift that will make! Congrats on your first pieced quilt!