My son had something similar to that right before he turned 2 years old. We had vomitting for 2-3 days followed by about 3-4 days of massive diarrhea (sp?), and then it took him another couple weeks to get his strength back. Poor boy couldn't keep anything down, not even water at first. We did go to the emergency room after a few days and he got an IV to get his fluids up. They also suggested popsicles and using a medicine syringe and squirting small doses of water every 15-20 minutes. I remember him being very thirsty and wanting to drink, so we'd give him water and he'd guzzle it down which would make him vomit it up. It was awful watching him suffer like that. The doctor said it was a rotavirus, which other than keeping their fluids up, there is nothing you can do it. Just keep them hydrated until it's gone. Good luck! I hope she feels better soon.