Mackenzie Phillips is going to appear on Oprah on Friday. This version will be live, and her half-sister Chyna Phillips, will be “speaking out” on the show.

Apparently Chyna is not denying that Mackenzie was a Daddy’s girl in a way that we don’t even want to get a mental picture of. She is saying that Mackenzie’s sibling are having a hard time in the wake of the release of the Mackenize’s book, High on Arrival.

Mackenzie’s stepmother, Genevieve Waite Phillips, who was married to Mackenzie’s father, John Phillips, when the alleged incestuous relationship between father and daughter allegedly occurred, has released a statement: “John was a good man who had the disease of alcoholism and drug addiction. He was incapable, no matter how drunk or drugged he was, of having such a relationship with his own child.”

Mackenzie Phillips

Mackenzie Phillips has been keeping one heck of a family secret to herself: She and her father, John Phillips, of The Mamas and the Papas fame, were involved in a consensual sexual relationship that went on for years.

The former One Day at a Time star first recalls having sex with her dad the night before her wedding to Jeff Sessler, who was a member of the Rolling Stones entourage, in 1979. People.com has released this excerpt from Mackenzie’s tell all book:

On the eve of my wedding, my father showed up, determined to stop it,” writes Phillips, who was 19 at the time and a heavy drug user, according to People.com. “I had tons of pills, and Dad had tons of everything too. Eventually I passed out on Dad’s bed.”

As Mackenzie’s life spun out of control, the incestuous relationship with her dad became consensual. People.com is reporting the following: ”I was a fragment of a person, and my secret isolated me,” she writes, according to People.com. “One night Dad said, ‘We could just run away to a country where no one would look down on us. There are countries where this is an accepted practice. Maybe Fiji.’ ”

Mackenzie Phillips’ book, High on Arrival, will be released on Wednesday, which is the same day an interview with the actress will be broadcast on Oprah. John Phillips died in 2001.

MacKenzie Phillips has entered rehab, her attorney has confirmed. The 48-year-old actress was arrested on August 27 at Los Angeles International airport for “carrying what appeared to be heroin and cocaine in baggies and balloons.” She has been charged with possession of both substances, along with unauthorized possession of a hypodermic needle or syringe.

Let’s hope this is a legitimate attempt to get clean (again) and not a ploy on the part of Ms. Phillips and her defense counsel to get a lighter sentence if she is found guilty on the drug charges.