Are you cloth diapering a skinny baby? Two of my boys are on the petite side: my 3 year old is short and stout, and my 1 year old is long and lean. Both fit one size cloth diapers differently. My Littlest is now 15 months old and hovers around the 18lb mark. He wears size 18m clothing. These are the one size cloth diapers that we still wear on the smallest rise setting!