H.W.
My son suddenly stoped eating when he was around the same age. We tried to force feed him and it got worse. It became a control issue. At that age the only thing a child can control is what they eat. So I followed some advice after many different things failed. The advice was simple - put her food down and you eat like you normally would, if she refuses to eat then put her meal in the fridge and serve it again at the next meal. Continue doing this until she starts eating again. She will eat when she is hungry. The best part of this is you are not getting angry or fustrated with her. You just offer her the meal and either she eats or she waits until the next meal to eat. Since the child gets no reaction from refusing to eat the child can't use it as a way to test boundaries. She will learn quickly to eat or go hungry. My son is now almost twelve and still stuborn, but he knows eat or go hungry. He chooses to eat.