Available sizes: 7 toddler,8.5 toddler,9 toddler,10 kid,11 kid,11.5 kid,13 kid,13.5 kid,2 kid. BIRKENSTOCK Sandals RIO. These stylish gold children's sandals are from the new collection of Birkenstock! Featuring a synthetic upper and a synthetic sole, the Rio is the perfect sandal for little girls! The sun will shine again!