after a litter do girls urinate all over the place (in the house)? is guess she is marking but it is not like her? Never had that or witnessed it from other breeders I learnt from. Can your girl get outside, does she let you know when she needs to go? The bladder may be weaker after whelping, but she should not be peeing in the house if she never has before.
Perhaps she is afraid to leave her pups, many Dam's like to not go far, have you tried popping her collar and lead on and making her go outside every few hours. Dam's quite frequently will hold their pee if they do not wish to leave their pups, perhaps she is just expelling in the house so as not to leave them, so lead her take her outside and she should go quickly so that she can get back to her pups.
As for food my own routine is. Scrambled egg in the morning with a bowl of goats milk, (on it's own this could cause the runs) next course is soaked puppy food with added mince, fish, chicken, next course meat/chicken/fish of the day with rice, then more soaked puppy food, rice will bind so I would put that in her diet somewhere throughout the day too, and then another bowl of goats milk. Bitches can be loose for the first couple of days with all the afterbirths eaten, but she should be solid again now.
Keep an eye on her, if she gets worse consult your vet.

Good luck with the litter.