Growing up only three years apart, Heather and Mallie Moore did everything together, good and bad.

"I can't imagine going back to where me and her used to be, you know," Mallie said.

At one point, they used drugs together and became addicted.

"Addiction had such a hold me that nothing else mattered," she added.

Mallie lost custody of her two children who were born drug dependent.

"At that moment in time, I loved my dope more," Mallie said.

When she became pregnant with her third child, she said it became clear that she had to change her life.

"I didn't want to go to the hospital and have my daughter and have her taken from me because I was at that point obviously," she explained.

By the grace of Grainger County Judge Duane Sloan, she went to drug court and then went to a halfway house in her hometown, all while her sister Heather was still using.

"I would call the police on her and tell him where she was," Mallie joked.

Eventually, Heather willingly committed a crime to get help.

"I actually went to prison to get clean because it was the only way I could get help because I didn't have insurance," Heather said.

Mallie never gave up on her sister.

"If it didn't help anybody but my sister I would still do it every single day if it didn't help anybody but her," she added.

Her prayers and drive did help her sister. Heather has now been clean for 20 months. After she was released from prison, she shortly became pregnant to her fourth child, Noah.

Mallie is now helping more people by sharing her story. She also works with the same drug court that helped her seek treatment.

"Don't give up until a miracle happens, one day at a time, and living in the moment is what I really stuck with during my recovery," she said during a news conference alongside Gov. Bill Haslam and counselor to the President Kelly Anne Conway at a treatment center in Chattanooga earlier this month.

"Going out and helping other people, that's how we stay clean," she added.

Mallie has now been clean three years and Heather has been clean for 20 months.

"We're like best friends. we always have been, though," Mallie said with a smile.