BOISE, Idaho (NewsNation Now) — Lori Vallow’s mental health has been the subject of speculation regarding the death of her two children.

Vallow is accused of murdering 17-year-old Tylee and 7-year-old Joshua. They disappeared in 2019, and their bodies were found in the backyard of her now-husband Chad Daybell’s home in June of 2020. Vallow and Daybell appeared in court last week.

The judge in the case stated that the couple’s mental health will not be used as they try to convince a jury of their innocence, according to EastIdahoNews.com.

Larry and Kay Woodcock, who are grandparents of one of the victims, spoke exclusively with NewsNation’s Ashleigh Banfield about their opinions regarding Vallow’s mental health.

“It’s just an excuse. Lori knows right from wrong,” Kay said. “They knew right from wrong. She knew right from wrong, and she didn’t have to offer up her children to be murdered, or to murder them. We still don’t know how all of that played out.”

Watch their discussion in the video player above.

Editor’s note: An earlier version of this article incorrectly stated that Kay Woodcock was Lori Vallow’s mother. She is not.