Swoon Baby is a division of the girls designer powerhouse. Serendipity Clothing. Swoon Baby offers girls clothing in sizes from infant to girls size 10. Swoon Baby has become a huge hit for its knit styles that wash and wear like a dream. Swoon Baby girls clothing runs generous by about a full size so we recommend ordering true to size as this will already have plenty of growing room. Swoon Baby clothing is a customer favorite here at Everything But The Princess. Moms love the darling styles, loaded with so many details and girls love the fun designs. Swoon Baby clothing for girls is a great line for sisters to match or coordinate and we offer a large selection in sizing from baby, toddler to girls size 10. Moms love the sistering that Swoon Baby offers for their family pictures, special events and just everyday looks.