you certainly have both ends of the spectrum with your responses here.
Me personally... it sounds like a virus that's going around. I would watch for dehydration, be sure she's getting plenty of fluids, but I would avoid fruit juice - that can make stools loose. I would sooner give her sugar-free Kool-Aid if you need incentive to make her drink more (but only as a last resort - we're water drinkers here). Encourage foods that bulk up stools - banana is a big favorite here for that. Multi-Grain Cheerios - my kids snack on those all the time.
I would also give her Acidophilus/Probiotics. They have really yummy strawberry chewables for kids. I give my son one every day, in addition to his daily yogurt. he seriously thinks it's candy :)
watch her stools for streaks of blood, black streaks, and don't fret about her appetite too much. Just make sure what goes in, helps to get her bowels happy again :) Hope she feels better soon... good luck to you