Since you seem to be new to quilting, why not have fun and learn a little more about quilting? First, add a more pins to help stabilize the quilt sandwich. Then you can stitch in the ditch using the sashing to guide you. SID is easy, and would be good practice for learning to quilt on your machine. (The quilt doesn't look so large that it would give you lots of trouble.) Finally, to add to the fun and quilting, sew a colorful button in the center of each heart. Your granddaughter can even help sew on the buttons--that's a good way to get her involved. Walmart has packets of colorful buttons in different shapes that are quite affordable--check on heart-shaped ones, but even simple round ones would be cute.