Somewhere over the rainbow bluebirds fly! The Bluebird Collection by Serendipity is comfy and cute in soft, cotton knit and blue and white gingham. She will love to twirl in the Bluebird Twirl Dress! This whimsical style features custom buttons and fun pockets. Cotton/Elastane blend. See Size Guide. xxs(12m-18m),xs(2t-3t),s(4t-5t),m(5-6),l(7-8),xl(9-10),xxl(11-12).