What Can One Do About Heavy Menstrual Bleeding In A Child Who Is On Primolut-N?

Doctor my daughter is 12 years and 9 moths years old her period start first time in 2 June duration roundabout 10 to 11 days.then next month start on time 2nd July but two days slow but 3 July to 8 July heavy bleeding and 10 July finish according to doctor precautions use 5 days primout N regularly morning and evening tablet.but now again after one week again start periods plz suggest me for 12.9 years girl what tablet is best Primolut N orDiane 35