Personalized Big Sister Superhero Youth T-Shirt. Big Sister Superhero! The big sister looks out for her younger siblings, just like a true superhero should. Great Youth T-Shirt - White for any super sis! 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.