My friend recently hurt herself but instead of calling an ambulance, she just lied in bed and kept repeating the shahada. I later asked why and she told me she wants to enter heaven but cannot stand her life and hates herself. So if you committed suicide but your last words were the shahada, would you still enter heaven?
I noticed many questions on this site are about matters that only Allah knows. The pattern is "If I do x good deeds will I go to heaven?" and conversely "If I sin this way will I go to hell?"
No one except Allah knows the Ilm Ghaib (knowledge of the unseen).
Allah tells us in so many Ayahs in the Quran that He (tt) is the only one who possesses the knowledge of the unseen.
Follow the tenets of Islam by using the Quran and the Sunnah of our beloved Prophet Muhammad (Salawaatulaahi Rabi Wa Salaamu 'Aleyhi) as your two weighty guides.
If a person is hurt and he/she has access to help (ambulance, etc) then he/she should not harm himself/herself by not getting treated. Instead, he/she should take necessary actions to save himself/herself.
What your friend did does not seem to be the right thing. She should have gone to the hospital or you could have called the ambulance.
Suicide is a major sin in Islam. It is a sin which has very dangerous consequences. A person would be killing himself again and again in hell (he would kill himself in the same manner in which he did suicide).
I advise you to visit www.islamqa.info and read articles about suicide. If your friend is alive call ambulance and urge her parents to force her to get treated. If your friend is alive you may inform her through her brother or through her parents about the punishment of suicide.
At islamqa.info you would also find various articles about how to attain jannah