Dressing up your youngest daughter can be a fun shopping experience. Baby girls shirts come in different styles to suit different occasions and different ages, while at the same time keeping a baby girl skin warm and comfortable. Baby shirts or infant shirts are usually made of the softest materials, sometimes 100% cotton, so they don't irritate younger children's skin. For toddlers and infants, be sure to use laundry detergent for babies to keep them clean and protected.