This is a very challenging situation because you are asking essentially how you can prevent someone else from engaging in harmful behaviors. The reality is you can’t. You can’t control another person’s behavior. You can’t help your girlfriend in the manner that you would like because she requires the help of mental health professionals. Laypersons are not mental health professionals and thus should not try to treat mental health problems.
The best thing you can do is encourage her to seek professional help. You might even search the Internet and locate a provider who can help. You should also speak to her parents and ask for their assistance, regarding treatment.
What is especially concerning is that she engages in self-harm behavior and has tried to end her life. That behavior is exceedingly concerning. If she might harm herself or someone else, report this to her parents, your parents, a mental health crisis team and/or the authorities immediately. Her instability and impulsivity may cause her to engage in dangerous or deadly acts.
Regarding suicidality, research shows that most suicides are impulsive, done on a whim. People don’t suddenly become suicidal necessarily; however, sometimes they make a decision to end their lives and act quickly, without much forethought. Research also indicates that most people who attempt suicide don’t want to die. They are simply attempting to end their psychological pain. This is a serious problem that requires professional help. This is yet another reason why you should report what you know to adults and or the authorities. She needs more help than you can provide.
Regarding your relationship, I understand your desire to be with her despite her problematic behavior but individuals who are mentally unstable have difficulty in relationships. It’s important for her to gain mental stability before she can effectively participate in a relationship. Encourage her to seek treatment and support her as much as you can. Don’t expect her to be relationship-ready at this time.
If you struggle with this situation, consult a therapist. It would help you to know how to interact with her. If you can, take a step back from the relationship and work on supporting her and her efforts to get treatment. That’s the best and most kind thing you can do at this time. It’s also worth repeating that should she ever become a danger to herself or others, call for help immediately. Good luck with your efforts. Please take care.
Dr. Kristina Randle