The remains of 7-year-old Joshua "J.J." Vallow and his sister, 17-year-old Tylee Ryan, were found on their stepfather's property

By Steve Helling
June 24, 2020 11:44 AM

The sister of Lori Vallow is speaking out after the discovery of the remains of J.J. and Tylee Vallow -- and acknowledging that she "was wrong" to support her sister.

Summer Cox Shiflet has been one of her sister's staunchest defenders, but has changed course after the bodies of 7-year-old Joshua "J.J." Vallow and his sister, 17-year-old Tylee Ryan were found on their stepfather's property.

"Words are hard and inadequate," Shiflet wrote on her Facebook page. "Trying to type through this pain is difficult. The last few months have been hard. The last week has been excruciating. Losing our precious Tylee and JJ in this horrific way is more than we can bear."

It has been a long ordeal for the family.

J.J. was last seen on September 23 in Rexburg, Idaho, when his mother withdrew him from school, telling the principal she planned to homeschool him. Tylee was last seen at a Sept. 8 day trip to Yellowstone National Park. After they hadn't heard from the children in months, their grandparents called authorities.

Joshua “J.J.” Vallow, at left, and Tylee Ryan
Rexburg Police Department (2)

In January, authorities gave Lori Vallow five days to produce the children and prove that they were safe. After she failed to do that, she was arrested.

Vallow has been charged with felony counts of desertion and nonsupport of dependent children, resisting or obstructing officers, criminal solicitation to commit a crime, contempt of court and willful disobedience of court process or order for failing to produce the children. She has pleaded not guilty and is being held on $1 million bond.

Chad Daybell, left, and Lori Vallow
Rexburg Police Department ; Madison County Sheriff's Office/AP/Shutterstock

The children's bodies were found earlier this month on the property of Vallow's new husband, Chad Daybell. Daybell has been charged with two counts of destruction, alteration and concealment of evidence. He has pleaded not guilty to all charges.

Authorities have not commented whether the charges will be upgraded against Vallow or Daybell after the discovery of the children's remains. An attorney for Vallow and Daybell has not returned PEOPLE's calls for comment.

Joshua “J.J.” Vallow, at left, and his sister Tylee Ryan

With the new discovery, Shiflet says that her trust in her sister was misplaced. "I was wrong," she reportedly wrote in her Facebook post. "I am an extremely imperfect person that loves my family with all my heart, and I wanted to believe the best in them, and I held out hope for the best possible outcome."

Want to keep up with the latest crime coverage? Sign up for PEOPLE's free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases.

Now the family is left to grieve the loss of the children.

"We had prayed our hearts out for them and hoped with all of our hearts they were safe," Shiflet wrote. "But we sadly have to face this new reality and our family will never ever be the same."