Girls Ruffled Shorts - "One Size". Great for little Princesses - & the ruffles are good for disguising appliances. Unfortunately they're not cheap - but they are a really good quality & should last with care. Available in White & Pale Pink.
The "Special Measure" is 46cm with not a great deal of verticle stretch. They have a lot of stretch horizontally so will cover a broad range of sizes. In the picture they are worn low (as hipsters are fashionable) - but would sit higher if pulled up like a full brief.