Diet for a 13 year old girl.?

ok well im 13 years old and i am about 165lbs and about 5 ft 3 in and I really need to lose weight to become at least 125 lbs in 4.5 months. I have an ab circle pro @home and i do rhythmic gymnastics. I eat a pretty healty diet so please can you help me.... AND NO MEAN COMMENTS OR ANY PPL SAYING I'M FAT! PLEASE HELP ME!