I would recommend getting a broad spectrum dewormer. Whipworm is very hard for even vets to find. They dog can have it and be tested 3 times and only come up positive 1 time out of those 3. So I would de-worm the dog for all worms, just to be safe. If she is that sick there is no telling just what she has.
Also I think you said she was not yet 6 weeks? If so she is in serious danger of Parvo. Without mom's milk to provide a little protection and no antibodies of her own she is very vulnerable. Keep her away from all public places. Adult dogs can carry Parvo and not be sick from it. She should not be exposed to any place that has dog traffic, or dog owners boot traffic, for her own protection. Once she has her 3 Parvo shots she will be ok.