Brief Answer:
FOLLOW THE ADVICES.
Detailed Answer:
Hello,
Thanks for writing to us.
The Very First thing, long time heavy menstrual bleeding since last child birth with NORMAL ultrasound scan is mostly suggestive of 
Dysfunctional Uterine Bleeding (DUB), occurs due to hormonal imbalance or 
progesterone deficiency as a result of dysfunction of ovary.
Here, I suggest to undergo complete hormonal profile like LH/FSH, prolactin, serum TSH/ T4, androgen profile, AMH (anti-mullerian hormone) etc along with blood Hb% and endometrial sampling. It will help to pinpoint the diagnosis.
Secondly, progesterone supplement (like DEVIRY etc) is the DRUG of choice to treat this condition and control bleeding. It can be given in combination with 
Tranexamic acid (like TRAPIC etc). Non-hormonal medication like 
Ormeloxifene can be used alternatively. Kindly, procure a complete prescription from your consulting Gynecologist.
Lastly, she would take healthy diet with IRON supplement & green vegetables, drink more water, avoid mental stress by regular meditation, maintain genital hygiene and take sound sleep. She can consult once with 
DERMATOLOGIST regarding black shadow under eye.
Hope, it helps for your information. Kindly, close the discussion if you don't have any other query.
Wish her good health and take care yourself.
Regards,
Dr Soumen
For future query, you can directly approach me through
http://doctor.healthcaremagic.com/Funnel?page=askDoctorDirectly&docId=63326