try the homeopathic: nux vomica (i recomend inthe strength of 30c, but whatever form you can get your hands on....)
i got food piosoning and a horrible tummy flu twice while preg., it saved me....otherwise i would have had to go tothe er for dehydration..i could not keep water down.....
i popped 3 in my mouth and with in 15 minutes could drink mild broth (miso in water) i suggest you try with your dd.
just pop one pill in her mouth, (they disolve) wait 15 min. and do another, wait 15 min and trysome spoon fulls of miso broth (that is a teaspoon of miso in 2 cups of warm water, it will ease her tummy and stay down better than water alone...)
you can't OD on homeopathics and you can't have adverse reactions with them, they just might not work for her body type, there is NO harm trying it.
like i said it saved me several times.