Did everyone know Michael had a secret sister after Joe's long term affair?

I don't know if it's old news but I haven't seen this before. It was printed by the Telepgraph who are usually ok but they do quote the Daily Mirror who are dubious, it might not mean anything as far as the hoax death goes but if it's true it may be another reason why Michael did not get on with his father, of course it may be BS I don't know.

http://www.telegraph.co.uk/culture/music/michael-jackson/6185704/Michael-Jacksons-secret-sister-JohVonnie-Jackson-says-she-was-rejected.html

yes it's an old news and I also believe that Michael would have been angry with Joe for the affair..Michael adored his mother and I think it was the horrible impact the affair had on Katherine that was more upsetting 4 Michael rather than what it did to him...and he also said that he couldn't understand when he saw Joe hugging JonVonnie when Michael and his sibilings were told to call Joe by his name not father.