In 2011, Upper West Side mom Yazmin Flores launched Little Vida, a Net-a-Porter for the 6-and-under set. Now, from September 27 to 29, she’s taking her drop-down menu of luxury boy, girl, and baby designers to a pop-up shop (355A Bowery, nr. Cooper Sq.; 212-925-3890). The haute kidswear ranges from more-well-known labels—a navy tulle skirt from Stella McCartney ($88); dusty, pleated chiffon dresses by the Zahara Jolie-Pitt–worn brand Pale Cloud ($192, pictured)—to hard-to-find European designers, including Italian-crafted metallic leather sneakers by Pepe ($136) and elbow-patch grandpa cardigans by Paris-based Louis*Louise (from $65). Face painters and mimes will keep kids entertained while parents browse, and on Saturday, fall and winter merchandise will be marked down 15 percent.