My female was the same size as your little puppy and she nursed fine. However, I would be concerned if she doesn't latch on and cries a lot. I did spend the first couple of days actually holding her on to the nipple because she wasn't that strong and would fall right off. After the first 3 or 4 days of that she got the idea and was strong enough to stay on the nipple without help. She is a fat little piggy now and turned out to be the bigger of the two pups. Good luck.
