Personalized Mermaid Princess 6th Birthday Toddler T-Shirt. 6th birthday Toddler T-Shirt - Purple with a beautiful little mermaid princess wearing a crown atop her red flowing hair and surrounded by cute fish and starfish. Text says THIS LITTLE PRINCESS IS 6. A toddler-soft cotton tee in look-at-me, big kid colors. 4.5 oz., 100% combed ringspun cotton. White is sewn with 100% cotton thread. Topstitched rib crew neck. Double-needle stitched sleeves and bottom hem. Shoulder-to-shoulder taping.