Usually I don't have to change my girl's diets much beyond switching them to a puppy or performance food - they are on a high-quality diet to begin with. Sometimes I'll add things like hamburger, liver, eggs, chicken, yogurt etc.
The first day or so after whelping, combined with the upheaval in her life, are probably the reason why she's not too interested in food at the moment. I suspect that shortly her appetite will start to increase on it's own, in which case I normally give them as much as they want (except in the case of dogs like Chili who will eat until they explode even without being pregnant
). If not, first have the vet check her to make sure nothing is wrong, then cater to her if necessary. She MUST eat enough to feed the pups and keep herself healthy, so if that means filet mignon so be it.
The first day or so after whelping, combined with the upheaval in her life, are probably the reason why she's not too interested in food at the moment. I suspect that shortly her appetite will start to increase on it's own, in which case I normally give them as much as they want (except in the case of dogs like Chili who will eat until they explode even without being pregnant