Personalized Sweetest Big Sister T-Shirt. Who's the sweetest big sister? Cute T-Shirt - Light Blue with adorable smiling cupcake with pink frosting and red cherry on top says SWEETEST BIG SISTER. Everyone loves our Custom T-Shirts! Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.