Personalized Sweetest Little Sister Youth Long Sleeve T-Shirt. Who's the sweetest little sister? Cute Youth Long Sleeve T-Shirt - White with adorable smiling cupcake with pink frosting and red cherry on top says SWEETEST LITTLE SISTER. youth long sleeve t-shirt. Shoulder-to-shoulder taping. Youth: S(6/8), M(10/12), L(14/16), XL(18/20)