Can people with anorexia have symptoms before they are actually considered "underweight"?

She is a normal healthy weight, but has little to no appetite and hardly ever eats. She will eat a couple bites and be full. If she forces herself to eat too much, she throws up because she's too full. She can not stand the cold. Even when it's slightly chilly outside she shivers violently, even with a thick sweater and a coat on. She is also very tired all the time and gets dizzy often. clumps of her hair fall out when she washes it, not sure if thats from being malnourished or not but she normally has thick, strong hair, and her hair is breaking. She has the symptoms, but she is just not underweight (yet).