your BMI is 27.9 which is overweight a healthy BMI is between 25 and 18
healthy for you would be any weight between 68kg and 50kg
you can work this out for yourself by googling a BMI calculator and putting in your height and weight
you should not worry to much though, you are 15 which means your growing, and your a girl so your hormones will be doing crazy things.
when i was 15 my weight was 76 and 'im only 158 cm. once i turned 18 i dropped so much weight and by 19 i was 58kg without diet or working out.
the teenage female body is a pain in the *** you will properly be up and down for the next few years so don't do crazy diets just eat right and eventually you will have a healthy BMI