First, rabbits do not eat every poop so don't force her to eat it. Second when did you get her and from where? If she was in a wire bottom cage, she probably never learned that she could eat poop so to here, that is not food at all. Many rabbits live out their lives without ever eating poop, yes mostly those bred for reasons other than as pets, but if your rabbit came from a place that doesn't let them have access to poop, she may not know a rabbit is supposed to eat it.
Feed her a proper diet of foods she will eat and, let her decide if she eats poop or not.