Personalized 4th Birthday Mermaid Tail Girls Newborn Layette. 4th birthday Newborn Layette - White party idea has starfish and mermaid tail with this mermaid is 4 message 100% combed ringspun cotton 5.8 ounce 1×1 baby rib sleeper. 3/8" flatlock binding at envelope neck and cuffs. Back sleeve flap to protect hands. Elastic opening at bottom. Infant: 0-3 Months