Good answers.
I would Add,
A good weight for puppies is 4 ounces. I have a 4.5 pound mother and she has free whelped every litter.
I have an x pen, I put the whelping bed in the x pen. I start putting the mother in the pen to sleep about a week before her due date so she gets used to it. About 2 days before her due date I leave her in there most of the time. She pretty much just wants to sleep anyway. But this keeps mom from wandering off and hiding to have her pups.
After the puppies are born, this is where they live. the whelping bed has tall sides on it so the puppies cannot crawl out. I put a heating pad under half of the bed, that way the puppies can get away if the get too warm.
When they start to move around more, at around 3 weeks, I replace the bed with tall sides, with one that they can get out of, I place a pee pad next to the bed. This introduces them to the pee pad right from the start.
I let mom in and out as she wants.
If I can answer any more questions, you can PM me.
Good luck with your litter.