Rosanne Cash is opening up about the turbulent marriage between her mother, Vivian Liberto, and her father, Johnny Cash. In a new documentary, the Grammy-winning singer admits their volatile relationship impacted her deeply when she was growing up.

Liberto's 13-year marriage to Cash ended in divorce in 1966, and it's been long overshadowed by his 35-year marriage to June Carter Cash, which has been the subject of numerous books and movies. A new documentary titled My Darling Vivian explores the ups and downs of Cash's first marriage, using interviews from Rosanne Cash and the couple's three other children, Kathy Cash Tittle, Cindy Cash and Tara Cash Schwoebel.

Cash launched his career as a recording and touring artist just one month after oldest daughter Rosanne was born, and his marriage to Liberto began to feel the strain as they faced long periods apart while he toured heavily to promote his records. The relationship became more strained as he subsequently became mired in addictions, and Rosanne Cash recalls that the stress led her mother to periods of deep depression and violent outbursts to the point where Rosanne lived in a perpetual state of anxiety, wondering if her mother might kill herself.

“I’m not saying this out of self-pity,” she tells the filmmakers (quote via Rolling Stone Country). “I’m saying it looking back from decades on and going, ‘That was f--ked up. That’s not how children should be raised.'"

That said, the documentary is not meant as a sordid recounting of the couple's difficulties. Rosanne Cash says her mother "faded into negative obscurity" after her marriage to Cash ended, and had to endure a lot of unwanted public attention focused on her former husband's subsequent marriage to June Carter, whom he'd met and fallen in love with during their marriage. The new film is intended as an homage to a woman who found herself in a very difficult spot, and it spotlights the loving highlights and the good times in her marriage to Cash using never-before-seen footage, photographs and love letters between the couple. Liberto also remarried after they went their separate ways, marrying a police officer named Dick Distin in 1968.

Liberto and Cash got the opportunity for a rapprochement of sorts at the end of their lives. She visited him two months after June died in May of 2003 and told him about a memoir she wanted to write about their marriage. Cash reportedly gave his blessing, saying, "Of all the people on the planet that should tell their story, I think it should be you," according to Rolling Stone Country.

Johnny Cash died on Sept. 12, 2003, at the age of 71 of complications from diabetes. Vivian Liberto died in May of 2005, but not before finishing her book. I Walked the Line was published in 2007.

My Darling Vivian is currently streaming via Amazon Prime Video as part of the SXSW 2020 Film Festival Collection.

See Pictures of Johnny Cash's Lavish Lakefront Estate: