Jill Duggar Dillard Says She's Still Angry at Brother Josh Duggar: 'Anger Can Be a Good Thing' (Exclusive)

Jill Duggar Dillard is still processing everything that happened with her oldest brother Josh Duggar.

"It's still really upsetting," she tells PEOPLE in this week's issue while discussing the release of her debut memoir, Counting the Cost, out Sept. 12.

In the book, the former 19 Kids and Counting star writes about the pain she and three of her sisters felt when a judge dismissed their "invasion of privacy" lawsuit in 2022— one they filed against the individuals who they claim released a private 2003 police report that detailed how Josh had molested them when they were younger.

"They were told as kids, 'This is a safe place. What you say is safe.' And it wasn't true," Jill's husband Derick Dillard chimes in.

The trial for the Duggar sisters' lawsuit was first postponed when Josh was charged with one count of possession and one count of receiving child pornography in December 2021. The Duggar sisters' "invasion of privacy" lawsuit was dismissed in February 2022 and Josh was sentenced to nearly 13 years in prison three months later in May 2022.

"Our attorney said Josh's sentencing was basically was the nail in the coffin for our case," Jill, 32, recalls. "It was the same judge that handled his case. But there's no reason it shouldn't have gone to a jury trial. It was just one of those moments [with Josh] that was yet again disappointing."

Still, she says, the anger isn't necessarily a bad thing. "People are quick to say, 'Oh, anger is bad,' but I'm like, 'No, anger can be a good thing.' Especially when it propels you to advocate for people finding their voice," Jill says.

She adds, "You have to just say, 'You know what? Even though this system failed us as victims and our desire for justice, and all of these people who just used and abused their positions and were not held accountable, we are still going to fight for victims' rights through Derick's line of work."

Derick, 34, who was a co-author on the book, is now an assistant district attorney in Oklahoma.

"I work with victims now every day and try and make sure the same thing doesn't happen to them," he tells PEOPLE. "We want to try and protect them, and actually try and make sure that we can follow up and be genuine when we say, 'This is a safe place.'"

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He adds that Jill and her sisters believed they were being protected when they initially gave their statements against their brother when they were still minors, which is why they're still so deeply disappointed the report was ever made public in the first place.

Jill adds, "We hope and pray that going forward that nobody ever has to be in that position that we were in. I knew that writing the book, we would have to address some of that, but I didn't want to go and rehash everything in detail because it is a very sensitive place for me."

She continues, "It was stuff that never should have been released in the first place. So yes, it still makes me so upset."

For more on Jill Duggar Dillard and Derick Dillard, pick up the latest issue of PEOPLE, on newsstands Friday, or subscribe here. 

Jill and Derick's memoir, Counting the Cost, will available wherever books are sold on Tuesday, Sept. 12.