The case that sparked the HBO documentary Mommy Dead & Dearest involving the Missouri woman convicted of killing her mom, who abused her by forcing her to be in a wheelchair and act like she was terminally ill, spoke in a new interview with 20/20.

Gypsy Rose Blanchard is serving 10 years in prison for second degree murder for her mother’s 2015 stabbing, which also involved a boy she met online, fell in love with, plotted the murder, and later running away together.

Gypsy said she never considered walking out of her wheelchair in public to expose the fraud perpetuated by her mom: “I honestly didn’t think about that,” she said in a clip. “I was always so afraid of her — afraid of the consequences after.”

She also said her mom chained her to the bed: “I think that she was very sick in her mind. For a long time I believed, like, we were best friends, and when I was younger she was my best friend. … other than my stuffed animals. And so I thought that she was a great mother. No complaints, we got along so perfect. I saw her as an angel that can do no wrong.”

She added: “She physically chained me to the bed, and put bells on the doors, and told anybody that I probably would have trusted that I was going through a phase, and to tell her if I was doing anything behind her back.”

The 20/20 interview airs Friday at 10 p.m. ET.