Great!! The discharge is normal, most likely her mucas plug. If it was green and had a very foul oder then that is a bad sign. If she's not already, I would take her to her whelping area. When she starts getting restless, laying down, standing, turning in circles, pawing and digging, thats a good sign one is on the way. Remember if she is pushing and straining for an hour and not producing a pup then you need to rush her to the Vet immediately. Enjoy watching, and try not to help too much, I have heard that if you help too much then it can sometimes cause them to abandon the litter leaving you to raise the pups yourself. Don't hesitate to help if she needs it, or if a pup needs it, but just enjoy watching if she dosen't need your help.
Good Luck!!