Here is the sacrificial shirt.
Then I eyeballed the length I wanted using one of J's too short skirts and went snip snip.
I wrapped my elastic around J to measure and sewed it into the proper sized loop.
Then in an effort to make my sewing projects a bit higher quality, I zigzagged stitched the rough edge. Someday there my be a serger in my life, but I'm still scared of them.
Then I put all three in her drawer without telling her. If I presented them to her as wardrobe options, she would have thrown a fit and refused to get dressed. This way, she discovered them herself and wanted to wear one every day, even after we had already wrestled her into a dress she had picked out. So we compromised and let her wear it underneath the dress. If petticoats become a trend, J totally started it.