Actress Mackenzie Phillips later tweeted a picture of her and Franklin, who played her mom on the same program.

CNN: 'One Day at a Time' actress Bonnie Franklin dies

Mackenzie Phillips acknowledged that her family members aren't happy about her decision to release the secret she said she's held for more than 30 years, but during her interview with Winfrey, she did have one sister in her corner: her on-screen sibling Valerie Bertinelli.

CNN: Mackenzie Phillips: Dad wanted me to be his wife

Chynna Phillips and Mackenzie's "One Day at a Time" co-star Valerie Bertinelli have since rallied around her.

CNN: John Phillips had checkered, sometimes sordid, life