
You need to stay with her and keep her in the whelping box with the puppy for the first three days when he should be suckling virtually non stop between naps to bring the milk in.
Some new Mum's are a bit slow getting the hang of things and you need to encourage the maternal bond.
She needs to stay with him except for toilet breaks for warmth and nourishment.
You should feed her in the whelping box, sloppy food in case her mouth is sore from cleaning.
You need to weight the puppy the same time each day and if it is gaining weight, or at least staying the same then he is OK, but should start to gain within a day or so of birth.