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

On her own in Indianapolis, Ann Romano was raising two teenage girls played by Mackenzie Phillips, already famous for the film "American Graffiti, " and a previously unknown Valerie Bertinelli.

WSJ: Bonnie Franklin, 'One Day At a Time' star, 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