It turns out there are a ton of tutorials for making sundresses out of pre-shirred fabric on line, and after reading a few I was ready to strike out on my own. The straps are 8" x 2" strips from my stash folded over twice and sewn, and I went for the two-side-seam model on the body itself.
The whole thing took *maybe* 45 minute to whip up, and little A *loves* it. In fact, the hardest part of sewing it was getting the dress back from her once she tried it on for "strap placement" purposes. Here's hoping for a summer where it gets a lot of use!
And thanks to A for being my lovely little model.