i missed the original post.. but is your sister self harming?
in fact
Diagnostic and Statistical Manual
The Diagnostic and Statistical Manual of Mental Disorders fourth edition, DSM IV-TR, a widely used manual for diagnosing mental disorders, defines borderline personality disorder (in Axis II Cluster B) as:[2][16]
A pervasive pattern of instability of interpersonal relationships, self-image and affects, as well as marked impulsivity, beginning by early adulthood and present in a variety of contexts, as indicated by
five (or more) of the following: 1. Frantic efforts to avoid real or imagined abandonment. Note: Do not include suicidal or self-injuring behavior covered in Criterion 5
2. A pattern of unstable and intense interpersonal relationships characterized by alternating between extremes of idealization and devaluation.
3. Identity disturbance: markedly and persistently unstable self-image or sense of self.
4. Impulsivity in at least two areas that are potentially self-damaging (e.g., promiscuous sex, eating disorders, binge eating, substance abuse, reckless driving). Note: Do not include suicidal or self-injuring behavior covered in Criterion 5
5. Recurrent suicidal behavior, gestures, threats or self-injuring behavior such as cutting, interfering with the healing of scars (excoriation) or picking at oneself.
6. Affective instability due to a marked reactivity of mood (e.g., intense episodic dysphoria, irritability or anxiety usually lasting a few hours and only rarely more than a few days).
7. Chronic feelings of emptiness
8. Inappropriate anger or difficulty controlling anger (e.g., frequent displays of temper, constant anger, recurrent physical fights).
9. Transient, stress-related paranoid ideation, delusions or severe dissociative symptoms
http://en.wikipedia.org/wiki/Borderline_personality_disorderif she is a strong match for this then i would suggest finding a therapist that knows what the STEPPS program is (And the said therapist will most likely refer to the condition as Emotional Intensity Disorder). your sister also needs to be ready to change.