No pineapple is not toxic to your dog, though if she ate the whole thing it likely has upset her stomach. The rind may also have caused a blockage as well and this is something to consider as well.
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.
I would start her on a bland diet of boiled chicken and rice to help settle her stomach. I am concerned with her becoming dehydrated as this is quite serious with dogs. I recommend giving her unflavored pedilayte to replace the electrolytes she is losing with the diarrhea. You can also give her One teaspoon of Pepto Bismol per 10 pounds of body weight for faster relief. The Pepto can be given with a small syringe....like the ones used to give babies medication. Slide it to the side of her mouth close to the cheek and slowly administer. She will swallow the majority of it.