How much fat should a 15 year old girl eat a day?

well. it's not fat that your eating it's the calories your consuming. It really depend on your weight/height. I am 5''5' && 158 pounds and in order to lose weight i must eat (max) 2076 calories! so form there i guess you can round up or donw on your height and weight and estimate your calories needed to maintain or lose weight, u cna also use (google) and search for a calorie calculator to have percise numbers. i hope i was of some help :) BTW u must run at least a mile a day on top of decreasing calories to lose weight . I was 174 pounds at one point and these things really helped me . GOOD LUCK :)