
I base my choice on the pups behaviour. I feed my bitches in the whelping box ands pups will often start to try and get into Mums bowl. Also I weigh my pups and if the rate of weight gain bottoms out rather than increasing it is time to help Mum out.
I start mine off on puppy food well soaked before hadn with hot (not boiling) water and add this to puppy milk formula to make a runny gruel. Plain puppy milk tends to make them choke.
As pups get older the mix gets to be more and more puppy food and thicker. They need to have access to a shallow pan for drinking water once on solids properly.
They should also have their first worming about this time, but I prefer to be sure that they have eaten wel to reduce any tummy upset.
As for the length of time Mum stays with them, pups can get all they need pretty quickly, but once they are less hungry she will be happy to stay with them more as they won't be harassing ehr so much.
Mu should be getting at least 4 times her normal amount of food at this time, (basicaly as much food as she wants) but once they are eating a lot her appetite shoudol reduce.
I do not diet Mum if she has got fat until after the post partum moult. If you have never expereinced it at 8 to 12 weeks after pups birth she will loose her coat, all of it to practically bare skin, and look awful.
This is normal and I keep my bitches on puppy food until they have finished this moult and started to grow thei coats back, only then do I see if they need trimming down in weight.