^^^ I agree 95 to 105 is good . But dont forget body frame , girl or boy ,height , thick boned , if you play sports. Muscle ways more than fat . But the average weight for a girls is like 126 pounds and boy is 127 pounds.
If you're not handicapped or have some sort of health condition beyond being overweight, you should be able to perform athletic activities at least on an average level to the rest of the kids around you. If you can't keep up with them, then you're probably over the weight you should be relative to your height and age.