(NewsNation) — Mary Katherine Smart was just 9 years old when her sister Elizabeth Smart was kidnapped out of the same bed.

Elizabeth was missing for nine months before she was located alive March 12, 2003.

Now, 20 years later, Mary Katherine broke her silence on NewsNation’s “Banfield.”

“I feel like I just assumed she would come back, and luckily, that’s what happened. I think there’s some things I understood and other things I didn’t. Fortunately, the outcome was good,” Mary Katherine said.

In June 2002, Elizabeth was 14 when kidnappers stole her from her bedroom in Salt Lake City. Her kidnappers, Brian David Mitchell and his wife, Wanda Barzee, took her captive for nine months. In March 2003, police found and rescued her in a Sandy neighborhood.

Mitchell was sentenced to life in prison. Barzee was sentenced to 15 years and released early on parole.

Families of victims are too often overlooked.

Mary Katherine and her dad Ed shared advice to the families of the Idaho victims, affirming that while things won’t ever be the same, they can get better with time.

“The process is gonna be unique to each of them. I’m not gonna pretend like I have all the answers because I don’t. … As time moves on, things get better. You learn how to cope,” Mary Katherine said.

In the past two decades, Smart has created the Elizabeth Smart Foundation, Smart Defense Program, and the We Believe You Campaign. She says her goal is to educate and spread awareness.

NewsNation affiliate KTVX contributed to this report.