Hi, thanks for your question and I understand your concerns. Your daughter is having an acute inflammation of her stomach and intestines (Gastroenteritis) possibly from contaminated food or water. Her lightheadedness results from her loss of water via the vomitus and diarrhea. The most important thing now is for her to have the lost fluid replaced as soon as possible. You should check her tongue, if its completely dry, it means she is severely dehydrated and requires the fluid to be administered to her through an intravenous line.In that cae, she needs to be urgently admitted in a newby hospital. If she is not severely dehydration, give her oral rehydration solutions to replace her lost fluid. Her elevated temperature means she requires antibiotics. What antibiotics she requires is determined by what organism is causing the symptoms. I would suggest she begins taking an empirical antibiotic, if its not included in her doctor s prescription, while she goes for a laboratory test involving taking a sample of her stool to detect the microbe. She would be fine. Best wishes to your daughter. Please reach me if you have more questiions.