Sounds like the beginning of gall bladder disease. She may need a hydascan to determine if her gall bladder is working correctly. I hope she doesn't have much pain. Bile is a nasty tasting green acid-producing liquid made in the gall bladder to help digest food. - I used to get relief by drinking grapefruit juice to which a bit of cooking oil was added.
The green liquid your daughter is vomiting up is called "bile".
Best thing to do is to try and eat something, like a piece of dry toast, or an arrowroot biscuit and to stay hydrated, by drinking water or light fruit juice (keep off the milk).
Well, did she eat something green beforehand? Vomiting is pretty much inevitable if you exercise too hard, and vomit is colored by what you've eaten in the past hours to day. Blood comes up looking like tar or coffee grounds, and is only bright red when you're bleeding quickly and it doesn't have time to digest. Since hers is green, maybe it's gatorade?
Make sure she stays hydrated, and get her to eat a little something when the vomiting stops.