Margaret Paterson, a Tacoma middle school math teacher, knows that it was tides and currents that carried her mother’s body to an empty stretch of beach on Vashon’s west side.

“It makes sense, from an oceanic standpoint,” she said.

But she also can’t help but find a bit of mystery, magic, even poetry in the way her mother’s life ended earlier this week.

Martha Scharpf, Paterson’s mother, walked into a chilly Puget Sound off of Titlow Park in Tacoma on Friday, Feb. 15, a few months shy of her 90th birthday. Her eyesight was failing. She was increasingly experiencing dementia. In a note to her daughter, she said she’d had enough and was ready to go.

But in ending up at Reddings Beach, Scharpf, her daughter said, came back home. Scharpf, a former Vashon resident, once owned Books by the Way. Her closest friends were from here. It was a place, Paterson said, that her mother loved.

“It’s like karma that she went to Vashon,” Paterson said. “The biologist in me knows that’s the way the tides worked. And according to the police department, things tend to wash up there. … But I think there is something kind of magical about the fact that she wanted to go back to Vashon.”

Scharpf’s body was discovered last Monday afternoon by a man and his two children who were out for a walk. The body was among a pile of driftwood on a quiet expanse of beach between Camp Sealth and Lisabuela Park. Initially, she was identified as an elderly woman from Tacoma. Authorities later released her name, noting, again, that she was a Tacoma resident.

But after The Beachcomber updated its story on its website, adding her name to the brief post, an email or two came in and a few queries were posted on Facebook. Wasn’t Martha Scharpf the former owner of Books by the Way? Wasn’t she one of our own?

“It’s such an amazing story,” said Carole Elder, one of Scharpf’s friends and a Vashon resident, after she learned the news.

Susan Montoya, a former Vashon resident and the woman who purchased Books by the Way from Scharpf, agreed. “It gives me goosebumps,” she said.

Paterson, reached Thursday afternoon, 30 minutes after learning definitively that it was her mother’s body that had been found on Vashon, said she’s completely at peace with Scharpf’s decision.

Her mother had long lived life on her own terms, Paterson said. She got her undergraduate degree from Stanford, then went back to school after her children were grown to get a master’s degree in gerontology and to launch a career as a retirement home administrator. She entered the Peace Corps at age 60, returned to the United States with a bit of money, moved into Paterson’s home in Tacoma and began to look around for her next adventure, Paterson said.

In her quest to decide what was next, she drove to Vashon and discovered that Books by the Way — then located in the yellow bungalow next to Pandora’s Box — was for sale. She bought the small shop in 1985, at age 63, becoming the bookstore’s second owner.

Twice, she moved it — first to Parker’s Plaza and then to the spot next to Frame of Mind, where it was a going concern until its last owners closed it in November 2011. Those who knew her described her as someone who loved books and poured many hours into her shop, revitalizing the small store. She was single-minded, no-nonsense, feisty and a bit cantankerous, people recalled.

“She was her own person,” said Donna Kellum, owner of Frame of Mind, who added that she was impressed by how hard she worked. “She got things done.”

Margaret Paterson agreed. “Her entire adult life was on her own terms. She did exactly what she wanted to do and made it happen.”

Scharpf sold the bookstore eight years later, in 1994, when she was 71, Paterson said. She continued to live on Vashon for a few years; her house was a mobile home in upper Burton.

“It was the perfect place for her,” Paterson said of Vashon. “She loved the lifestyle on Vashon. She loved the people.”

Paterson said she has a stack of 15 letters from her mother’s home at the assisted living center in Northwest Tacoma next to Titlow Park where she moved four months ago. “Almost to a person, they’re people she met on Vashon,” Paterson said.

Paterson, too, has a Vashon connection. She taught science at The Harbor School from 2003 to 2006, commuting to Vashon from her home in Tacoma. Her daughter, Kate Paterson, did the commute with her, graduating from Vashon High School in 2006.

Scharpf’s life in recent years had become a struggle, Paterson said. She was experiencing some dementia and had macular degeneration and was losing her eyesight.

“For a lady who likes to read, this was just devastating,” Paterson said.

Over the last few years, Scharpf talked to her daughter about ending her life when the time felt right.

“The right moment came,” Paterson said. “I’m proud of her — that she was able to accomplish this final goal. This is what she wanted.”

“We will never know if it was difficult or if she just pushed forward until the cold overtook her,” Paterson added. “We are all smiling that she ended up on Vashon. I only wish she could be here to laugh with us.”