I actually have a copy of Cheryl's autobio 'Sweet Poison' - written in about 1990, and advertised as a full pager in 'US Magazine' as a
'best seller' 
Incidentally, the book's about her life as a Stevie impersonator, and how she ended up in jail for supposedly cheating people who gave her $$ to promote concerts.
Anyways, in the book Cheryl mentions her own family members, and not once made any reference to being Stevie's 'daughter'. Her only ties to the Nickses was that she became good friends with Stevie's mother Barbara for awhile.
Cheryl Cusella being Stevie's daughter (which is new to me) is just a ridiculous rumour.
