Good day doc my daughter is 11 year old and having...

What is the nature of period bleeding ?
nature : usually you bleed around 50 cc per period 
duration : usually its around 4-6 days , but it can last as few as 3 days , and as much as 7 days 
shape : its may look like a flow in first 2 days , then tend to be like spotting after that 
color : bright red , and may be accompanied by blood clots , or vaginal discharge at early or late time of the period 
What to take period bleeding ?
1. first you can take the medication the especialized for the bleeding such as :
-  dicynone 
- tranexamic acid
2. then you have to take hormonal medication to stop bleeding and period abnormalties such as :
- duphaston 
What if the bleeding didnt stop ?
- reconsult your doctor again and do the needed tests 
- the needed test 
1. physical examnation by doctor 
2. productive hormones tests
3. blood test
4. ultrasound imaging test
5. endoscopoy for productive system ( if needed )