Please help if あなた can..

あなた need to go talk to her, no matter what it takes. Tell her that it's not the end of the world, that あなた really need her. And tell her that her best friend wouldn't want her to do this. She would want her to be strong, and carry on without her, but keeping her in her memories.

Well, that's a really difficult situation the one your sister is passing. I don't want to sound as a heart-less person but the best thing is that あなた talk yourself with her after a little while, and if that doesn't work, I highly recommend あなた to talk with your parents to take her to a psycologist.

I've gone to the psycologist and believe me, is a really good experience and relaxes あなた from everything, doesn't matter the situation, he//she will be a great help.

And don't think that the psycologists are for crazy people または people with some brain problems, is for helping people. Really I highly recommend them ;D

There is nothing あなた can do!!!! Just TRY to act normal! Put 食 in her room and she may eat after a while!! Try texting her, if that doesn't work i am not sure!!! Hope this helps!!!

u know...i've never had this happen. i'm usually the on in the bedroom...sadly. no one can ever cheer me up when i'm like that. then again, i don't have anyone here exept mom...and she can never help, cuz she don't ever know what 2 say.

Tell her it wasn't her fault and nothing could stop it. It was God's path for her, and nothing can change that. Try to find her a new friend and tell her it will be okay.

I hope she feels beter and may God bless her