Personalized Monkey Big Sister Youth Long Sleeve T-Shirt. Big sister Youth Long Sleeve T-Shirt - White with adorable little girl monkey ballerina in a pink tutu and ballet slippers holding a bouquet of flowers says I'M THE BIG SISTER. youth long sleeve t-shirt. Shoulder-to-shoulder taping. Youth: S(6/8), M(10/12), L(14/16), XL(18/20)