Hello there
From what I've read, your suppose to be sure your pup has something in their tummy. Not eating for 24 hours isnt good for anyone. If they arent eating their regular food, you should at the least try to get em' to eat a cracker of piece of bread (to coat the stomach) and that should stop the vomiting. If it continues, she could have eaten something bad... and you might want to get her to the vet... Hope this helps