The size 6 in janie and jack is closest to the following:
Brand Label Weight (lbs) Height (inches)
H&M 7-8 years - 50 inches
Hatley 10 - 56 inches
LLBean 10-12/M - 53 - 58 inches
Marimekko 11 yrs/ 146 cm - 58 inches
MiniBoden 11y - 57.5 inches
Petit Bateau 10Y 48 - 53 lbs 54.5 inches
janie and jack 6 44 - 52 lbs 52 - 62 inches