The bust is measured from underarm seam to underarm seam across the front. Double to get the circumference.  Double to get the circumference.  The length is measured from the shouldler seam straight down to the hem.  A size 1 is a Small/Medium and a size 2 is a Large/X-Large.
1: Bust is 21" (42" around). Length is 47"
2: Bust is 24" (48" around).  Length is 49.5"