Regards to Sizing: Pieces fit fairly true to size, if anything run a touch big. There is no need to size up. If you are in between sizes and are petite, you could size down (so for example if your daughter is a 3, you could size down to a 2 if she is petite.)
Model is 4.5 and wearing the size 4-5. She usually wears a size 5. She is 42.5in tall.