W.M.
You can try a pony tail for one and if the sides are short and will hang out, put them in barrettes or bows. Also, you can try to bribe....tell her that apparently she likes to eat her hair so she won't be needing any gum, candy, dessert, etc Whatever it is that she really likes. That would work with my kids! Or...you can put a hair gel or hair spray lightly on the ends that she sux on. I have gotten my hair in my mouth before b/c of the wind, etc and it tastes bad! Just until the habit is gone and then stop.
Good luck! W. M.