I have a cousin who is overweight and had irregular periods, I believe she was told that she had this because she could go months without a period. Naturally, no period no ovualtion one would think. She just had a baby in August. I have another cousin very petite and thin who has it also. She also suffers from no periods. I think what I am getting at is please take your daughter to the doctor and get the diagnosis confirmed. Polycystic Ovarian Syndrome can affect anyone no matter what physical traits someone has. Good luck.