Should I send a letter to my bsister who hates me?

I cut off contact with my birthfamily last month, after almost 9 years in reunion. I had little to no contact with birthmother (though we had multiple phone calls and face to face meetings, she is just too unstable for a real relationship. She has substance abuse problems).I had ongoing weekly contact with bfather for nearly 9 years, as well as several visits, etc. I ended the reunion after my younger bsister (age 16) decided that she hated me, and that she did not want me in her life(she is VERY jealous of my relationship with her father, and while she and I used to be close, everything went sour when she hit puberty) True to their familys way of thinking, my bfatherҒs ENTIRE family (his parents, siblings, aunts, etc.) decided that if my 16year old bsister didnt approve of the relationship I had with HER family, then they didnҒt approve either. They said that my bsisters happiness and comfort was all that was important, and that they didnҒt want my bfather to have a relationship with me if it hurt her. She is very spoiled and bad tempered. My bfather did nothing to stop, prevent, or help this situation. He took no responsibility for his daughters actions, did not reprimand her to attempt to speak to her about it at all (even after she told me on numerous occasions when I would wish her a happy birthday to F*** off.) As a child I had always felt unwanted by them (they kept siblings before and after me, I was the only one to be adopted.), and to essentially be told by 9 out of 10 birthfamily members that I was, indeed, unwanted way too painful to bear. After months and months of agonizing and posting on these forums, I decided to end my reunion, despite my bfatherҒs protestations. He cried when I told him, but he had enabled the situation for TOO long. He refused to stand up for me, or explain to his family my sisters jealousy. Anyway, to my question. I told my bfather that if and when my bsister decided that she was ready to either have a relationship with me, or at least tolerate me and not be cruel to me, he was welcome to call. Until then, I could not deal with feeling so rejected anymore. I told him that maybe one day I would not be so sensitive, and I could be able to handle bsisterҒs negativity and the lack of his familys support for our reunion, but until then, we needed a break. I thought about sending my bsister a message on her myspace, or even a little handwritten letter, explaining that if she ever wants a relationship, IҒm here. That Im her sister, and not a threat. That I will never hurt her like many of the women in her life have. If nothing else, I want to put the thought in her mind. Plant the seed of communication, so to say. I must admit, I am afraid of her reaction. Any contact may prompt her to send me a cruel response, and I cut off this reunion to avoid these feelings of being hated and unwanted. IҒm reluctant because I am afraid she will hurt me intentionally, for the 100th time. This is expressing vulnerability on my part, and she has taken advantage of this in the past, and HAS hurt me on purpose. What do all of you think? Send the message/letter, or just let her grow up a few more years? Risk being hurt, or risk never hearing from them again? I dont know if sheҒll ever be grownup enough to not see me as a threat, or to love me. I have no expectations. I want to send the message, but Im afraid of being rejected for the thousandth time.