Perhaps Cesar can convince you. Following is from
his site. Week 8 is where you can expect to come into your new puppy's life if you have chosen to adopt through a reputable breeder. Make sure that you coordinate with the breeder and your veterinarian to determine that the puppy has been wormed prior to the adoption and to find out what shots, if any, the puppy may still need.
Because the puppy has spent his early weeks developing in the company of his mother and his brothers and sisters, his mental processes should be mature enough to handle the move from the breeder to your home, and he should be receptive to training. Still, just because your puppy has been socialized doesn't mean he doesn't still need your guidance from day one! Don't forget to get right to work setting your new pack's rules, boundaries, and limitations and consistently enforcing them. Your new puppy is easily influenced by your pack leadership, so keep it balanced and consistent! Housetraining and introduction to the sights and sounds of your puppy's new home should begin right away. Positive experiences associated with the various new elements of your puppy's life will help ensure a smooth transition. And don't forget that your puppy is still a social animal! If you have no other dogs or pets, try to find calm, vaccinated dog pals for him to interact with. This could prevent issues that may arise later on from lack of socialization.
It sounds like your pup is losing her mom/littermates way too early. Yes, she may be healthy, but I just think you'll be getting a pup who likely to not well adjusted emotionally. At this point, it wouldn't matter if the breeder kept her longer, because the most damage is done by removing mom at such an early age.
You sound young, and we've all made mistakes by getting that pup from the wrong place. (I posted my experience early in this thread.) I truly hope we don't scare you off, and I'm saddened that you can't learn from our experiences. I just wish breeders like this were put out of business.