Mackenzie Phillips

During Mackenzie Phillips' appearance on The Oprah Winfrey Show Wednesday, where she claimed to have had what she says was an incestuous relationship with her late father, John Phillips, she received a surprise visit by her One Day at a Time co-star Valerie Bertinelli.

Mackenzie Phillips says father, Mamas and the Papas' John Phillips, raped her

"I had no idea what you've been through," Bertinelli said to Phillips. "I feel regret that I wasn't there for you as much as I could have been. I was so wrapped up in my own life and my own, you know, drama of being in my life, because I've dealt with substance abuse. And so I wasn't paying attention to my sister, and I feel bad for that."

Phillips was scheduled to appear on The Rachel Ray Show for a One Day at a Time reunion with Bertinelli last year, but she was arrested and charged with two counts of possession of narcotics at the Los Angeles International Airport.

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Prior to Bertinelli's appearance, Phillips discussed her past experiences with her father and drugs in detail.

According to Phillips, her father taught her to "roll joints" by the age of 10, and at 11, she had tried cocaine from a cereal bowl her father kept "filled to the brim." Phillips said her drug use progressed quickly. "I was probably 16 or 17, and my father shot me up for the first time," said Phillips. She also said that at 18, she slept with Mick Jagger while her father was aware it was happening.

Phillips recalled being on tour with the Mamas and the Papas around age 18 and saying she would begin "waking up after drug-fueled events with my pants around my ankles and my father sleeping beside me." She believes that she was the only daughter to whom her father made overtures.

Mackenzie Phillips' family split over star's incest claims

The incest all came to a stop, according to Phillips, when she became pregnant without knowing who the father was. "He knew it might be his child," Phillips said of her dad, who paid for the abortion. It was then, Phillips says, that she never let her father touch her again.

Despite everything Phillips says her father put her through, she says she does not hate him. "I think my father was not a bad man," she said. "He was a very tortured man and sort of passed that torture down to me."

Phillips, who has a 22-year-old son, says he has been "incredibly supportive" of her journey.