Whitney Houston’s mother wonders if she could have saved her daughter’s life.

In an upcoming memoir, Cissy Houston, mother of late singer Whitney Houston, talks about her daughter’s drug use and her worries about teenage granddaughter Bobbi Kristina Brown. In Remembering Whitney, which will be released Tuesday, Houston admits that she was aware of Whitney’s drug use and still wonders if she could have helped prevent her drug-related death in February 2011. “I’m angry she died alone, in those conditions,” she writes. “She started partying and she didn’t really know how to stop. I used to wonder what she was doing at night, where she was.” The memoir also addresses Houston’s current concern for Whitney’s daughter Bobbi Kristina, 19, who has publicly struggled with the loss of her mother. “She’s not handling it good. None of us are,” writes Houston. “It doesn’t mean that she is going to follow her [mother’s] same path. She could but anybody could. I don’t want to jinx her. I’m trying to make sure she doesn’t.” She reveals that when Whitney entered drug rehab in 2005, she brought her daughter along for part of her treatment. “I think Nippy [the family’s nickname for Whitney] wanted her to understand what she was struggling with,” she says. “She wanted to explain it to her, maybe so Krissi wouldn’t wander down the same path herself when her time came.” Cissy Houston will appear on Oprah’s Next Chapter on Tuesday to give her first exclusive in-depth interview since Whitney’s death. Article Link…