After 30 minutes of searching.. I am out of ideas.
I believe it was natural causes, And not a sudden death. (Because the media never seemed to take notice, and her boyfriend says " i shall keep my promises to you now matter what" on her myspace, Which COULD mean that she knew she was soon to die, and made some death wishes. Or it could mean something totally different

)
Not knowing, Is going to bug me. haha.
RIP