xBaibaixKittyx
Well Miss, I think the best thing for your sister at this point would be some extreme therapy. A doctor can analyze her situation and medicate her accordingly, and while it's not the best thing to say, it may be the best option here, and the safest one! If you're sister is threatening to kill herself, it may be wise to think of her health before her opinion, especially if she's acting this immature.
if your sister is anything like me... THAT IS THE WORST THING YOU CAN DO! that will either put the rest of the family on some sort of vengence/murder/screw-you-over-when-you-need-her-most list that she would keep in her mind, or start her on a hobby known as spree killing when she gets out...
burning_eyes my suggestion is to tell her why these things happened to her, and if she won't listen to that, hide all knives and anything else that she uses as a weopon from her and take her keys to the house and the cars, if she then starts studying ways to kill people, then put her in an orfanage and switch your names so it will be harder for her to find you and pray to your god that you will stay safe...
this is what my family should have done instead of sending my to the mental asylum, where they have plexiglass windows and they take your shoelaces and drug you so much you get high OR die then send you back to your house... and yeah, that sounds like your sister is almost exactly like me personality wise...
burning_eyes