Love your quilt! Definitely SITD, but I'd handquilt a different design in each group of 2 white squares. A heart, a few different flowers, the date of their wedding, their names, a wreath, a sun & moon, etc. You can find lots of things to quilt in those blocks, and that would make it extra special for the happy couple. If you don't want to handquilt then I'd stick with something easy, like a large heart in each of the 4 block squares.