Personalized 21st Birthday Infant Dress. 21st Birthday Infant Dress - Heather has colorful bday balloons and slogan that says Party - 21 Rocks. This infant girls fine jersey dress combines soft comfort with a sweet, simple style that is perfect for everyday wear. Made from lightweight jersey fabric, it feels gentle against delicate skin while allowing easy movement for play and all-day comfort. The classic short sleeve design and relaxed fit make it ideal for casual outings, photos, or special moments. Durable stitching helps the dress keep its shape through repeated washing, making it a dependable choice for parents who want both comfort and practicality in baby clothing.