I have a 15 year old female that seems to be developing at an odd rate. She started her period at about 13 but she has not deveolped breasts. She has gained alot of weight in the past two years, she has gone from being active to not so active, she is tired alot, and the weight gain is mainly in her abdomen. She drinks water all the time, could this be a problem? What do I need to have checked? Is she normal?