Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you with your wee one today. I do apologize that your question was not answered before. Different experts come online at various times; I just came online, read about your wee one’s situation, and wanted to help.
Diarrhea at this stage is not normal but it is not uncommon. This is because your lass will have a weakened immune system after pouring so much of her own body resources into her pups. Therefore, this often leaves recent mums vulnerable to picking up infections or having issues with worms or protozoa.
With all this in mind, we'd want to take a few steps to help her. First, if she hasn't been wormed recently, it'd be ideal to do so. You can also cover the pups at this stage. In regards ***** ***** there are a wide range of wormers that can be used for mum and pups, but Panacur (fenbendazole) would be considered our ideal here as it can be used safely on pups and covers some protozoal causes of diarrhea too.
Further to this, you can consider trying her with a dog safe anti-diarrheals. As I am sure you appreciate, these would not be a cure if her diarrhea is being caused by an infectious agent (ie bacteria will require antibiotics, parasites or protozoa will require anti-parasitic treatment, etc). Still it can slow the diarrhea to aid the body to absorb more water/nutrients then it would have if the diarrhea were unchecked. Furthermore, these treatments will coat the GI and could just settle the GI upset. In regards ***** ***** options for your wee one, the one we most commonly use in dogs is Kaolin/Kaopectate (http://www.petplace.com/article/drug-library/library/over-the-counter/kaolin-and-pectin-kapectolin-k-p). It is safe to use if she is still nursing and is available from your local pharmacy. Furthermore, Protexin Pro-Fiber, Propectalin, Fast Balance (which is available OTC at vets, pet stores, and even Amazon) would be another option. All will slow diarrhea and the last few have the bonus of providing support to the delicate good bacteria of the GI. So, you can consider trying these as a short term means of trying to soothe that upset GI.
Overall, diarrhea isn't normal at this stage but is very common. Therefore, you can start the supportive care for your lass at this point. Of course, if she isn't settling in the next 24 hours or is unwell with this, then we'd want to consider a check up with her vet +/- fecal testing to pinpoint the cause and get her on to an antibiotic if need be.
All the best,