a friend of mine just got a bunch of newborns and size one diapers given to her by a friend who says her child is already in a size 2. this baby is month old and so tiny. my daughter is 2 months and I don't even remember her being That small and she's only in size one. she says week the diapers go by weight. but size ones go ask the way up to 18 pounds. why would she think get baby needs a size 2