Her sisters are upset, her stepmom calls her a liar, but Mackenzie Phillips isn't backing down from her claim of a long-term sexual relationship with her dad.
She hopes to become the public face of incest, not a post anyone would want to hold, but one that represents an issue she says gets too little attention.
"If I've started a national dialogue that's going to help people face these issues, then I'm forever grateful," Phillips, 49, said Friday via satellite on Oprah.
Mackenzie Phillips, who revealed her shocking secret in a new memoir, High on Arrival, appeared for the second time this week on The Oprah Winfrey Show.
She returned to Oprah to face the doubts from her family about the nature of her relationship with John Phillips, founder of the band The Mamas and the Papas.
Bijou, Chynna and Mackenzie Phillips.
On Friday's show, Winfrey read comments made by John's ex-wife, Michelle, who was also a member of the band and later Mackenzie's stepmother:
"I have every reason to believe it's untrue," Michelle Phillips said, adding that Mackenzie has a history of mental illness and drug abuse.
Mackenzie Phillips, who also says she became pregnant, possibly with John's love child (which she aborted), didn't take the accusation sitting down, although she has by no means attempted to deny her long and troubled history of drug use.