Your dog needs to be seen by a veterinarian immediately.  The average time between delivery of subsequent puppies is 20-60 minutes, it can be as long as 2-3 hours.  Eight hours is too long between puppies.
The veterinarian will start with an x-ray to make sure there are still puppies in the uterine body--it is uncommon though there can be only 1 pup per litter. 
Depending upon the condition of mom the veterinarian may decide to give an injection to stimulate labor--although because there was a stillborn this may not be an option.
Surgery is the treatment of choice in a case of dystocia--the inability to give birth naturally due to fetal oversize (pups are too big), abnormal birth canal, or uterine weakness. 
This is an emergency--the sooner she is seen the better chance of saving the puppies and the mom!

 You may have waited too long already.  Get that dog to a vet immediately.  No ifs ands or buts.  Good luck and please get your dog spayed as soon as a vet says it is permissible.  All of this is so irresponsible in so many areas.  I'm sure you love your dog, but you need to think of these things beforehand. 

 It is an emergency you need to get her to the vet before she dies!!!!!!!!!!!!!!!!!