My 3 year old went through this about a month ago. It lasted so long that she got dangerously dehydrated at one point. The doctor said it's most likely the Norovirus going aroud (the cruise ship virus). I would think she was in the clear, she'd be eating, running around, acting like normal and then wake up in the middle of the night throwing up 2 days later. It was the most frustrating thing ever and lasted about 5 days for us. Some last up to 10!! I hope this isn't the case for you. Every time she throws up, do the same old thing...no fluids until she hasn't thrown up for more than an hour. Then, introduce 1 tsp of water/pedialyte every 15 minutes. Use the zofran too! Did they give her the dissolving kind, hopefully? I asked why she would seem fine one day and then sick the next, and apparently it's just how the virus moves through the body. Weird. Anyway, she's over and it and no one else got it. Phew. Keep your sink full of diluted bleach and water and sanitize all day long! Lastly, it's possible she has caught a second virus or ate something too fatty or with too much fiber that has upset her still sensitive digestive track. Keep it bland for longer than you think you would need to. No milk products either!! That's a big one. It's not possible to catch the same bug that she just had. It's still moving through her system, GI related or a totally separate virus.