i would be really worried about the 2oz little one that is tiny, normally at birth they should be at 3-4 oz in weight, was there any chance that this little one was concived after she was pregnant? keep a very close eye on her make sure she is feeding and is keept nice and warm as she will probley have a bit more trouble keeping warm then the others. make sure she gets enough nursing time and that she isnt being pushed aside by her litter mates.