What can I tell my diet crazy daughter?

My daughter had anorexia a few years ago and, she's never really gotten over watching what she eats. She's at a good weight now about 107-110 lbs at about 5'3. She's 16 years old. She has a fast metabolisnm but she won't believe it.she barely ever eats what she wants to at restraunts and places like that. She ordered a salad but she wanted a club sanwhich from cheddars. She looked up the salads nutrient facts and found out it had 1,200 calories and she got so angry. She plays soccer for about half the year. I wish she could just eat what she wants and enjoy it beause she's young what can I tell her to convince her that its okay to eat what she wants.???