Hello,
This is Dr. Christian. Welcome to JustAnswer. A few questions will help me get a clearer picture of this situation:
By my count that means she had her puppy about 15 minutes ago (correct me if that's wrong) so in this case don't worry. It may take another 45 minutes to an hour to have one. The second will typically be easier since the first was so big. Here's a link about birthing in dogs to help:
http://www.petplace.com/dogs/normal-labor-and-delivery-in-the-dog-2/page1.aspx
If you have more questions please let me know.
Dog Veterinarian
12 years of veterinary experience in canine surgery, medicine and behavior