
The thing is the bitch will be feeling a conflict between her attachement to the family and her babies. Mother nature tells her not to leave pups at all in first few days as constant feeding is what will build up the milk, as initially it is mainly colostrum.
If you have had a baby yourself you will have found that the first 3 days you are almost constantly feeding, and then the next morning you wake up as if you have rocks on yor chest. this is when the real milk comes in, and then the gaps between feeds lengthen as there is more volume which fills the baby/puppy up.
If the bitch ishn't staying with ehr pups enough in those first few days a good milk dupply MAY not so easily establish. That is why she needs to stay calm and focused on the job in hadn away from other animals in the house. I do tend to sit with a first time Mum as this reasures her and she isn't worrying about being all by herself with this big task.
Bitches that are less members of their family seem to be closer to their instincts, and more self reliant.