ya know what.... I'd make the smallest repair possible, as neatly as possible, and just 'fess up. This isn't for sale, it's for family. Your GD will love it all the more, and she'll think of you every time she sees that spot. Quilts are for loving and using, IMHO, and not for preserving. Give her a few years of loving it, and it will need repairs anyway.
Be proud of this quilt, it's gorgeous.