I agree to keep her hydrated but do wait to give her something to drink after vomiting. I would also be very careful as to how much you give her. After vomiting wait 30 minutes then give her a few sip of clear fluid (apple juice or pedialyte) No orange juice or similiar drinks with too much acidity. Then if she is able to keep that down give her a little more after another 30 minutes increasing the sips as you go. As long as she is sipping something she will be fine. But if sipping is causing her to vomit more that is worse. Make sure she goes to the bathroom at least six times through out the whole day or if in diaper six wet (don't have to be soaken, just wet) diapers a day. If throwing up I usually keep a bowl bedside and sleep in the room so I can catch it. Otherwise my trying to make it from my room in time even with the bowl next to her i was always late. If she is throwing up for more than a day and it doesn't seem to be going away I would go see the doctor.