My little girl was born weighing 7lbs and 12 ounces, she's already been through almost two bag/packages of diapers, she is a week old, how much longer until she gets into a size one? Im only curious because i want to know if i should open a large box of newborn diapers or buy a couple more packages of newborn sizes and wait to exhange the large box for a size one or bigger? What are yall's experiences with how fast they change diaper sizes?