RIVER FALLS, Wis. — Standing at the gravesite of her three daughters, Jessica Lee Peterson looks at the polished granite marker for a quiet moment, then speaks.

"It's hard to believe it's been 10 years," the River Falls woman said. "It feels like just yesterday sometimes."

Her girls were 11, 8, and 5 years old when their father killed them 10 years ago Sunday in an unconscionable act of hatred. The brutality of the crime shocked people far beyond this city of 15,000, a story that found its way into tabloids around the world.

The trial was swift, and Aaron Schaffhausen was sentenced to life in prison. He's never going to be released.

A decade after her three girls were taken away, Peterson has found purpose in keeping alive their memories: Amara, 11, Sophie, 8, and Cecilia, just 5. She stays close by talking about them often, and visiting the playground built in their memory near her house. This summer, she will release a book about their lives.

She has her own lifelong sentence to serve, one she tries to carry with grace, she said in a recent interview. Her pain has been eased by others, from close family to kind strangers who know her only as that grieving mother.

"I would be lying if I didn't say I feel guilty sometimes for enjoying life," she said while seated at the dining room table of the River Falls house she shares with her husband, Matthew Peterson. The two married in 2013, and have two young children, plus his two daughters from a previous relationship. They had their first date just days before the girls were killed. He never met them.

A surprise visit

Jessica and Aaron first met in Mankato, and moved to River Falls in 2006. They had three girls, but divorced a few years later.

Schaffhausen had been threatening toward Jessica and the girls in the past, but it seemed in summer 2012 that he was making up for his bad behavior, said Peterson. He made a surprise visit while Jessica was at work and the girls were home alone with a babysitter. Jessica told him he could stay and visit the girls as long as he was gone before she got home.

He called her later that day with a chilling statement, part of which was: "I killed the kids."

Peterson's memory of what happened next is spotty, a common reaction to deep trauma. She remembers talking to a 911 operator for 45 minutes as she raced home. She never learned the operator's name, nor spoke to them again, but thinks of that person as the first in a long line of people who helped her survive.

At the funeral, she invited everyone, including her ex-husband's family. She wanted it to be about the girls and not her. And she made a decision: "I decided very early on that I did not want to numb myself, with medication or maybe other things," said Peterson. She wanted to feel the joy of the good days she had with her daughters, even if it meant feeling the pain of losing them. She wanted to feel it all.

Some of the people close to her wanted to feel nothing, to shut it out. She's learned that everyone processes grief differently, that there's no right way to do it.

A community's care

Nothing came easy at first. Her trips to the grocery store could be upended when she found herself sobbing over the sight of a jar of peanut butter. The first time she made it through the aisles without crying, a clerk who knew what Jessica was struggling with cheered her on. "You did it!"

It would become one of hundreds of interactions with local people in River Falls that convinced Peterson to stay put. At least there people understood her story, she said.

She still marvels at the help she got from the leadership of Affinity Plus Federal Credit Union, which held the mortgage to her old house. Affinity Plus foreclosed on the house and razed it, donating materials to Habitat for Humanity before selling the lot. Proceeds of the sale went toward a new playground in honor of Amara, Sophie and Cecilia. The Tri-Angels Playground at Hoffman Park opened in 2015, built with $550,000 in raised funds. It sits near the cemetery that holds some of the girls' ashes. Across the street is their old elementary school, Greenwood.

When Affinity Plus invited Jessica to speak at their all-staff meeting, she went simply to say thank you.

"And then it morphed into a talk about how people can feel impotent in the face of tragedy, but Affinity Plus showed just how powerful individuals and organizations can be in combating darkness. I spoke about how the individual employees may have felt like they did nothing but how their actions of simply working for an organization can help bring about true change," she said.

The experience left Peterson with hope: She could talk about what happened and turn it into something positive. Soon she found herself making public speaking engagements. She found she wanted to talk about her girls. She wanted to carry them forward.

Telling their story

Soon after the girls' deaths, Jessica began sharing things about them on Facebook. It was sporadic at first, but by late 2013 she settled into a rhythm. She started writing letters to her deceased children, first as therapy, and then as the foundation for her book.

"It was very, very therapeutic," said Peterson, a Washington County social worker.

Five years ago her writing got more ambitious, and she started to dig into what had happened.

"I would hit these moments where I'm going, 'I'm crazy. Is anybody really going to read this?'" said Peterson.

She connected with a published author, Rick Paulas, and he helped her with structure and writing. She thought about self-publishingbut wanted a more professional approach. A lot of the feedback she got from publishers was that the story was too dark.

Finally, one of her husband's old classmates put Peterson in touch with Written Dreams Publishing out of Green Bay, Wis.

She wrote much of the book while living with Matthew and their blended family not far from the cemetery. For the hardest part of the book, the section that recounts the day that her girls died, Peterson headed to a remote Wausau, Wis., cabin with plans to spend a week by herself. Just before she left, she visited her old neighborhood for the first time since the girls died. It had been seven years.

Now that the book is finished, Peterson can't wait to share it. She has 450 pre-orders, but doesn't know the exact date it will be available. She titled it "Thistles and Thorns," named for a dinnertime conversation game she plays with her children. For Peterson, it's heartening to know that people want to hear the story of Amara, Sophie and Cecilia.

"So many of the people around you have suffered losses," she said. "If I can help just one person weather the storms that life brings us, it lessens the pain a little bit.

"Plus," she added, "I just like talking about my kids."

To buy the book

Information on Jessica Lee Peterson's book "Thistles and Thorns" can be found online at thistlesandthorns3x.squarespace.com.