Hi A H,
My kids also went through this a few weeks back. So here is my advice
1) if she hasn't stopped the vomiting then do not give her any food or liquids until it has stopped for 24 hours.
2) You first want to start with clear liquids like gatorade, water and popsicle, you can even give her chicken broth to replenish the salts she has lost. If she keeps that down move on to dry foods like toast and crackers and dry cereal.
3) If you are at the poinjt that all of the vomiting has stopped and are back on the mend of eating again then follow the BRAT diet. This is B=BANANAS, R=RICE,A=APPLESAUCE AND T=TOAST. Watch the applesauce though it can give them diarreha and send you the wrong way.
4) If she is running a fever or even a mild one give her tylenol and motrin and alternate between the both of them. If you time it right and give it to her early enough you should be able to give her tylenol twice during the day and motrin once and then give her motrin again before she goes to bed.
But if it is the samething my kids had milk and milk products made it worse. These things continue to feed the virus and keep it going. If you are going to give her anything close to milk or dairy make sure it is SOY, this will stop feeding the virus.
My kids had the vomiting for about 4 hours and then diareha for another week. It took us 2 weeks to get completely better.
Also you may want to go through and clean all of her toys with bleach and water. Not just her toys but anything she may have come in contact with, chairs, chair legs, tables, etc.
I'm a home child care provider and all of my daycare kids and my kids got it. The only 2 that didn't was myself and my older son. My husband got it and he is at work all the time. We were surprised when he came down with it. You should also wash all her bedding in hot water. I know it seems a little excessive but anytime any of my kids get sick or daycare kids, the parents and I go through and disinfect everything tob to bottom. We have kept our sicknesses to almost nothing this year. The only time they have been sick was when they had this exact thing. We also disinfect everything once a month.
Hope this helps you, W.