Please help!

My brother-in-law went out of town for a week and left his pregnant dog in our care. Well, she had her puppies in our backyard on Sunday. There are 12 of them. She absolutely will not move so they will be here for a week or more till she is willing to go back to my BIL's.

The first few days she wouldn't leave her puppies except to poop or pee. Suddenly today she is sitting outside the box while they are crying and searching for a nipple. She does go in there every now and then to feed them, but is spending most of her time outside the box.

I've never had a dog and I don't know the first thing about newborn puppies. My BIL is an irresponsible 22 year old and has no idea what he's doing. He comes once a day to check on them. I'm a stay at home mom so I try to check on them frequently, but the dog barely knows me and growls if I get too close to her pups, so I can't do anything or really check the puppies health. My husband is diligent about checking on them but he works a lot. I feel like this all on me and I have no idea what I'm doing.

Anyway, I guess I am wondering if it's normal for a new mom to put some distance between herself and the puppies? Any help is greatly appreciated!