Personalized Big Sis Girls Cute Sister Announcement Toddler Long Sleeve T-Shirt. Big sis Toddler Long Sleeve Tee - Charcoal for a girl has colorful lettering that says BIG SIS with flowered border for a 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.