Personalized Colorful Cupcake and Confetti Girls 12th Birthday Youth Long Sleeve T-Shirt. Celebrate your little one's special day with our Colorful Cupcake and Confetti Girls 12th Birthday apparel and gifts! Our selection of unique and creative birthday products are sure to make your kids, babies, and children smile. youth long sleeve t-shirt. Shoulder-to-shoulder taping. Youth: S(6/8), M(10/12), L(14/16), XL(18/20)