Blackmail by Family Member citing suicide

My Sister-in-law has sent me a suicide note and picture showing of her trying to hang herself. In the letter she has written that my father-in-law, mother-in-law, my wife and myself are torturing her and that's why she is committing suicide. She actually did not commit suicide. I want a legal advice to protect all involved. I personally have not spoken a single word to her or my brother-in-law. Funnily she has put my name also in the letter. It is a clear case of Blackmail. They are trying to get my mother-in-law pay for their home etc.