Personalized I'm Going to be a the Big Sister T-Shirt. Whether you're looking for a special present for a new sister, or a fun way to announce a new addition to the family, our Big Sister Elephant collection has something for everyone. The sweet elephant designs are sure to bring a smile to any big sister's face, and our range of products means you can find the perfect gift for any occasion. 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.