I apologize, I misunderstood your question. Childhood Bipolar is difficult to diagnose because there is not clear criteria of what the symptoms are in children. I would like to refer you to this National Institute of Mental Health explanation of Bipolar Illness in Teens:
The way to get it officially diagnosed is to have her evaluated by a child psychiatrist or child psychologist.
The behavior you describe also fits the criteria for Borderline Personality Disorder.
Teenagers and Borderline Personality Disorder
Currently, teenage girls are the group with the highest risk for developing BPD, although the condition does strike a small percentage of boys as well. If parents suspect that their child may have Borderline Personality Disorder, they should watch for the following signs and symptoms of the condition:
- Reckless behavior - such as driving too fast or having unsafe sex with multiple partners
- Suicidal thoughts
- Self-harming behavior
- Intense bursts of anxiety or depression
- An inability to control one's emotions
- An inability to maintain personal relationships
This excerpt is copied from the following website:
This JA forum is not a good place to seek a diagnosis because the diagnostic process requires interviews and questionnaires and perhaps personality tests, all of which a child psychologist would do in a standard psychological evaluation.
So the information I have given you is for educational purposes only.