If you are a boy, 122 to 150 pounds is OK. If you are a girl, 113 to 138 pounds is OK. A 4’10” girl’s normal weight is 81 to 99 pounds.
Your friend is about 77% of her healthy body weight. But if she eats food every day, several times a day and doesn’t throw it up, then she is probably just thin for her height rather than anorectic. If you want to know more about eating disorders, look at the anorexia or bulimia topics. Pre-occupation with weight is just one of the many symptoms used to diagnose an eating disorder.
Losing a lot of weight during adolescence is not recommended (how much did you lose?). Adolescence is a period of growth. Better you grow into your weight by getting taller during a growth spurt than trying to lose. Also, exercise is a great way to restructure your body’s composition, lose fat, gain muscle.
If you think you look OK, then why do you think you need to lose more weight? Sounds like you are unhappy with your body or are unhappy with the way you look, in spite of losing weight. Some of that is part of being a normal teenager. If you think about your weight a lot, you should talk to someone about your thoughts. A psychologist or dietitian would be appropriate for you to discuss your weight concerns with. You could also talk to your parents or an older relative whose opinion you respect.