Gracie,
Does she like milkshakes? I make one with a banana, skim milk, a little vanilla, a couple of packs of equal (or sugar if I need more carbs) in the blender - then drop in a coupe of ice cubes and blend well.
It makes an easy and fun to drink that might appeal to your daughter...my 16-year-old adds peanut butter to hers and ALL my kids drink these. They are best when the banana is on the ripe side, because you need less sweetener, but the banana shake is easy and very good. We always use skim milk and they are thick and yummy. Good luck with your picky eater!
Ann (pottervb)