Is Regestrone Suggested For Prolonged Menstruation?

Hello Doctor,

My 13 year old daughter, got her first period this past Jan and it was all okay. She didn't have it again for about two months. However now, she has been having period for little more than a month with really heavy flow. Took her in to see the Gynecologist and she prescribed Transxamic acid for 10 days along with Iron pills. When she was taking these pills, her period reduced by little bit but has not stopped completely. As it turns out, my sis-in-law, who is also 17 years of age too has this very same problem. Is this hereditary? I would kindly like to hear what your opinion might be on this matter. My daughter weighs little less than 90lbs. I hear about meds. such as Regesterone or Primolut-N but am not sure about them.

Thanks you,

Niomi