Thanks for the additional information. Usually after an hour it is considered an emergency and you should have a dog seen by your vet. However, a little extra time between horns of the uterus is not unusual. The uterus is shaped like a Y with the pups in each horn. So sometimes it takes a little time for the pup to move down. Now if a pup is partially out, you can grasp the pup, but do not pull. You grasp it to stop it from slipping back up into the female but don't pull. This can sometimes help a pup be expelled with the next contraction.
At this point though, she might be in trouble and need vet care. Read the following sites on difficult labors and deliveries.
Here is another article on dystocia.
If this was my girl, I'd go ahead and have her seen. Your vet may be able to just give her a shot to strengthen the contractions. He can also evaluate her and see if a c-section is necessary or not.
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