Beautiful quilt for your granddaughter. I love the fabrics!

You could tie it, but stitching in the ditch would be nice as well. The starching of the backing is a great idea!

Beautiful quilt as well :)

She is a lucky girl to get such a lovely quilt.

I think you should quilt it, but practice on a small piece first. I think SID would work, but it is not easy. I did wavy lines over seams on my first quilt and that worked well, or use a decorative stitch. Just remember if you use walking foot that the design can't have any backward motion.

It is a beautiful quilt.

I don't baste with thread, but spray baste with 505. Then I take it to the machine and just ... well, remember when we were kids and we'd do the scribble drawings and then color them in with different colors? That's basically how I start and then I get going into a real (hahaha) quilting mojo.. turn on some good music (some have said drink a glass of wine) and relax..and before you know it you'll be done with it in no time.

If its the first time you will be quilting something, try a few practice pieces first. I just used the decorative stitch on my machine and quilted along all the lines. (Stitched in the Ditch, its called.)For practice pieces I used a 6 inch square with batting and backing from junk fabric. Go around the edges, make a few squares in the middle, or corner to corner, just to see what the stitch looks like and to get the feel of it. You will find what you like and then quilt that precious baby's quilt. I love it.

You could pin it together and stitch in the ditch between the squares. That way you'd retain the 3D effect. It's also a good way to start out quilting.

I did a 3/4" x over the joins and then large stich with double embroidery thread to the next join and the the x and sew on. Looked great and a little different than just tying.
X - - - - - X - - - - -X The X actually catches all four squares.

I chickened out with the machine quilting! Such a coward I guess. lol but I like the idea of the Xs and I do hand embroidery. I have batting cut to the right size and backing will be flannel. Will have to think on it.....