Trina Turk black & white knit sundress. Size Large?

Fun striped Trina Turk sundress - all knit. Fabric content and some measurements in photo. It has a lot of give! Armpit to pit can stretch to 23 inches flat. Waist stretches to 22.5 and bounces back. Hips stretch to 25 flat. Length from back if collar to bottom is 30. Some light pilling can be seen under close inspection and bright light. Tagged as Large, but that’s questionable to me. I’d say medium.