To cure the immediate problem you can start by mixing 1 teaspoon of pumpkin into her meals to get her regular again. If you need to you can add some more until she go's.
Sometimes constipation is from not getting enough fiber into your dogs diet or because she isn't getting enough fresh water. If this becomes a problem you may want to look into increasing fiber into her diet.
Another reason for constipation can be a blockage from something she ate such as garbage, or a broken bit of bone or toy, if you believe this may be the case of the constipation, I would highly recommend a trip to her vet. When a pet has a blockage, they may exhibit any of the following symptoms: vomiting, loss of appetite, distended belly, an absence of feces or a change in the feces, blood in the stool or vomit, drooling, and retching or trying to vomit with the meal coming up or nothing coming up. If your pet exhibits one or more of these signs a trip to the vet is highly recommended.