Personalized Half Marathon My 1st 13.1 Run Toddler Sweatshirt. Cute half marathon running Toddler Sweatshirt - White outfit says my 1st 13.1 run for girls. Keep your little one cozy and stylish with this soft and durable toddler sweatshirt. Designed for comfort and ease of movement, it features a classic fit with ribbed cuffs and hem for added warmth. Perfect for everyday wear, playtime, or chilly outings, this sweatshirt is made to withstand the adventures of an active toddler