Personalized Sister Worlds Best Big Sis Toddler Long Sleeve T-Shirt. Big Sis World's Best Toddler Long Sleeve Tee - White has pretty pink sports style logo for the new big sis or your favorite sister A classic for Fall, Winter and Spring, these long sleeve toddler t-shirts are sure to be a staple in your child's wardrobe. Whether layered or alone, this t-shirt is soft yet durable enough to stand up to your toddler's playtime demands.