give her 100% organic juice ..... make sure it says 100% fruit juice .. not from concentrate cuz then ur sure it is actually fruit juice not a fruit drink.
orange juice is good if she will take it ...its kinda bitter .. try smashing some strawberries into juice .. they are loaded with vitamin c ... 3 large ones have 10 times more than a normal size orange
stuff with good anti oxidants too like cranberry and grape
maybe delute it some with filtered water ... cuz pure fruit juices tend to be rather strong in flavor