Experienced mommy question?

My 3 year old has had decreased appetite for about 7 days. For the last three days she has eaten less than a normal sized snack for the whole days intake, and has drank very little fluids no matter how hard we try . She has also thrown up 2 times each night for the past 3 nights. Very low grade fever if at all. Seems to have plenty of energy during the day. Any thoughts or ideas? Taking her to pediatric clinic in the morning.