There is a size chart & additional information listed in each product!
Capri is 9 months old and currently wearing size 6M-9M.
Sivan is 5'3" tall, weighs 118 pounds, is 25/26 in jeans, and a 34B. She wears a Small in all styles.
IN A NUTSHELL HERE IS HOW THE SUITS ARE RUNNING:
+ Black - True to size
+ Rosé - True to size
+ White - True to size
+ Leopard - Size up
+ Stripes - size up