Until the making of Whitney, a new documentary about Whitney Houston’s life, her mother had no idea that she and her brother (both her biological children) alleged to have been molested as children by Dee Dee Warwick, sister to Dianne Warwick.

Whitney’s sister-in-law produced the documentary directed by Kevin Macdonald, which gives special behind the scenes footage of Whitney over the decades. The movie is the second one released this year — the first was Whitney: Can I Be Me, which spotlighted her relationship with assistant, Robin.

“It was deeply a revelation for her. You think about her, and it being a bit overbearing for her to hear — and her kids not telling her. That’s pretty tough to have to deal with,” said Patricia Houston, her sister-in-law.

“I don’t think you can explain anyone’s life from one particular event that’s happened to them. But I think that it’s certainly fair to say that it’s maybe, in my opinion, the major contributor to Whitney’s unhappiness,” Macdonald said. “That and the fact that she never talked about it, and that nobody in the family talked about this and clearly it happened as you’d learned in the film.”