Personalized Lil Sis Unicorn Girls Sister Announcement Youth T-Shirt. Cute little unicorn for a new baby or the littlest sister in the family comes on a Youth T-Shirt - White. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.