Warning: The below article contains discussions of sexual assault.

Only after his death did 19 Kids and Counting alum Amy Duggar King discover the reason her family members kept her way from her grandfather Jimmy Lee Duggar.

Amy opened up about that family secret in a new interview with People as she discussed her debut memoir, Holy Disruptor: Shattering the Shiny Facade While Getting Louder With the Truth, due for release on Tuesday, October 14.

The former TLC star said that when she was a child, she wasn’t allowed to be alone with Jimmy. “I wondered all the time,” she recalled. “I asked. I asked my mom, I asked my grandma, and they obviously were going to protect the answer. They didn’t want me to know that information growing up.”

But after Jimmy died, Deanna Duggar, Amy’s mom, told her that he was a “predator,” as Amy explained in the book. “I honestly did not know why until my mom and I spoke after he passed away,” Amy told People. “But I obviously assumed. I always had assumptions as to why, but it was never spoken about.”

Amy added that she knew Jimmy wasn’t allowed to take her to school, watch a movie with her, or play with her on a trampoline. “There were so many things, and I just knew that that’s how it was,” she said.

Also, Amy’s grandmother would lock Amy’s bedroom door every night, and Deanna would check on her as well, Amy said.

Once Amy learned the reason behind those protective measures, she and Deanna “sat there and cried” together in an “intense bonding moment” they’d been needing for their entire time together, Amy said.

“I mean, looking back, oh my gosh, I could have been a victim, too,” she added. “It’s crazy to think it was so close to me in so many ways.”

Amy’s new book also addresses cousin Josh Duggar’s criminal record. As People recaps, Josh previously admitted to molesting multiple people, including four of his sisters, and he’s currently serving a 13-year prison sentence for receiving and possessing child pornography.

“Writing was the most difficult thing I’ve ever had to do,” Amy told the magazine. “I pushed myself to my limits. I cried all the time writing it, but I just wanted to be brave and tell the truth.”

If you or someone you know is the victim of child abuse, contact the Childhelp National Child Abuse Hotline at 1-800-4-A-Child (1-800-422-4453). If you or a loved one are in immediate danger, call 911.

If you or someone you know is the victim of sexual assault, contact the Rape, Abuse & Incest National Network‘s National Helpline at 1-800-656-HOPE (4673). If you or a loved one are in immediate danger, call 911.