Not for in whelp bitches as I have boys but...
Although I feed predominantly raw, I always keep some chicken stock or boiled chicken 'gloop' (bones removed) in the freezer. I find it's handy if any of mine seem bit off colour, or to tempt them to eat kibble from time to time. I freeze it in silicon muffin trays so it's quick to defrost.
Food ready to go is always a good idea for lots of eventualities. :)