Personalized Big Sis Girls Cute Sister Announcement Long Sleeve T-Shirt. Big sis Long Sleeve T-Shirt - White for a girl has colorful lettering that says BIG SIS with flowered border for a sister. Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL