Personalized Retro Rainbow World's Best Big Sister Toddler Dress. Whether it’s for a birthday gift or just because, this stylish apparel is a great choice for any occasion. It’s designed for comfort and style, making it ideal for everyday wear or special family gatherings. Your big sister will feel extra special wearing this, reminding her of her important role in the family. Your little one will be adorable and comfortable in this 100% combed ringspun cotton 1x1 baby rib dress!