Stray and her Puppies

Question
I have a dog myself and she has been bread 3 times so I am not completely ignorant however I know that there are differanced in breeds and sizes so I am seeking more advice.  A few weeks ago we noticed a stray mama dog running around and did our best to send her home (she had on a collar so we thought she was just wondering from home during the day.)  Well as time went on she got really skinny then last week we found her and her four puppies under our house.  Due to preditors we have taken all five to the vets, had them deflead, and they are now taking up residence in our bathroom.  These are mutts through and through but some of the obvious breeds in these sweeties are bull dog and lab.  The mama looks like she might have some whipet and our groomer said australian sheperd.  Anyway, mama stands about knee high and the puppies have little paws and short legs.  On to my questions.  #1 We are trying to figure out how old these babies are.  They are moving around ok and have their eyes open; however, they do not yet have teeth.  I have seen them go to the bathroom without stimulation, but the mama still does this most of the time.  What's your closest guess as to the age?  I am guessing somewhere between 2 and 3 weeks, but my husband thinks older.  #2 Is it normal for some breeds to have clear runny noses sometimes?  They all do and our vet didn't say anything about it when he checked them over.  I didn't know if maybe this was a puppy trait in some breeds.  #3 One little puppy isn't doing as well as the others.  She is eating and stuff but she just isn't as active.  Sometimes I can pick her up and she just flops.  I brought this up at the vet visit, but he seemed to think that it was the worms that they had and that it would clear up after they were dewormed but it hasn't.  I spend a lot of extra time with this particular puppy and have started supplemental feedings.  I know with my miniature pinchers puppies that I had to sometimes supplement sugar water because of blood sugar drops.  Could this be the same thing?

Thanks for your time and patience.  I just want to do what's best for these little guys and give them a chance.  (I have found a home for the mama and 2 puppies, and I'm trying to convince mu husband to let me keep the little runt when the time comes.)

Thanks,

Barbara

Answer
Hi, sorry for the delay in getting back to you.  At the time you wrote, the puppies had to be about 3 weeks old, but probably not 4 weeks because of no teeth.  Teeth start to show up around 3 weeks.  Thats when you can start slowly weaning them to mashed up puppy food soaked in warm water.  
Yes some breeds can have runny noses as long as it is clear.  Can be caused by dust irritating their noses.  
As far as the one pup, Worms may make them weak, but not flop over.  I would almost think something neurological is wrong with the puppy, possibly caused by malnutrition.  Hope this helps, and I hope the little one is doing better.

Dawn