Depends on whether you're toned or flabby. Depends on how big boned you are. Depends on lots of things. What do you see when you look in the mirror? If you look like you have too much flab, then you need to lose some of it and gain some muscle.
The previous answer by paxiled is poorly written. Telling a 17 year old female to judge her own healthiness by looking in the mirror is absurd. But I think the idea of muscle mass was vaguely put out there so I am going to follow those intentions. Technically, nadanichuirrin, you are still in a normal healthy weight range for your height, but are you healthy? You may know that muscle weighs more than fat. If you are concerned about your weight, look at your exercise habits and see if there's anything you want to change. Do you balance your exercise with cardio and weight training? Do you balance your diet with all the food groups? These are the questions you may want to ask because your weight is normal.