How adorable! This is a JcPenney's Fantasia white nylon and lace camisole.  It does have adjustable shoulder straps to help get the fit just right.

Tag reads "32".

Measurements (inches) are shown in the last photo; taken with item flat, buttoned/zipped, and unstretched.  Double when a circumference is needed.  Please use as an approximation, and compare to a garment you know fits you well or your own measurements. 

Thanks for looking! Please reach out to me with questions! From a smoke-free environment.