“My heart is broken that I’ve lost my mother this past weekend,” Mariah Carey posted in late August. “Sadly, in a tragic turn of events, my sister lost her life on the same day.” While the Grammy winner was able to be with her beloved mom, Patricia, before she passed, the story with the 55-year-old’s late sister, Alison, 63, is more complicated.

In her 2020 memoir, The Meaning of Mariah Carey, the singer alleged that when she was younger, Alison and their brother Morgan had drugged and tried to sell her, saying that maintaining a relationship with her siblings made her feel “emotionally and physically” unsafe. (Both siblings denied the claims and sued for emotional distress.)

A source exclusively tells Life & Style that Mariah’s older sister had struggled with addiction over the years and the Glitter star deliberately cut her out of her life. Now she’s dealing with the repercussions. “She had a lot of ugliness with her mother growing up too, but she was able to work through it and forgive her,” explains the insider. “With Alison, she’s grieving not just her sister, but what could have been.”