Personalized 3rd Birthday She is Fierce Girls 3 Year Old Youth Long Sleeve T-Shirt. Cute 3 year old girl birthday design with colorful flowers and quote that says and though she be but three she is fierce on a Youth Long Sleeve T-Shirt - Royal Blue youth long sleeve t-shirt. Shoulder-to-shoulder taping. Youth: S(6/8), M(10/12), L(14/16), XL(18/20)