Prolonged first period

[Worried-Mother]

My daughter is 14. She got her first period on 26th December but as of today 22nd Jan, she is still bleeding. Her doctor has prescribed tranxemic acid 1000mg thrice a day but the bleeding slows down but it is still there. Her iron and thyroid reports are clear. She is booked for a pelvic ultrasound in ten days but that is still a long time and then the wait for the results. I am getting very worried as to how we can stop the bleeding and what could be the underlying cause for this? Can someone please share any insight. I have been unable to sleep and I am not sure how long she can just sustain this bleeding without it affecting her health.