The size 20/ XL in Ralph Lauren is closest to the following:
Brand Label Weight (lbs) Height (inches)
Hatley 12 - 59 inches
LLBean 16-18/XL - 64 inches
Marimekko 12 yrs/ 152 cm - 61 inches
MiniBoden 12y - 60 inches
Ralph Lauren 20/ XL 127 - 138 lbs 66.5 - 68.5 inches