My daughter has her menstual cycle but has to change pads within every hour. is this normal for a teenager?

Probably not: Changing a pad hourly, due to heavy flow (menorrhagia) is not normal, but is fairly common among teens. It can lead to anemia, with subsequent fatigue, or even fainting spells. She should see her pediatrician, fp, or gyn. Most often, medication can solve this problem, often without a pelvic examination. Encourage her to see the doctor.