Hi geo, From what i was told the petite sizes are the same as the regular sizes except you add two inches or less (or more) to the mid-section or the waist area (according to your measurements). The petite sizes are for women who are 5'3" and the regular sizes are for the women who are 5'6". So to summarize compare your measurements for the regular sizes to the measurements for the petite sizes and check the center back and center front measurements. if there is a difference of 2 inches, slash the pattern at the waist and spread 2 inches and retape the pattern. You may have different measurements for front and back. hopefully this helps.
