Florence Heene never knew her biological father.

The 71-year-old Belgian woman first started to suspect that the man she called “daddy” was actually a step-father when she was 12 years old. That’s when she found her mother’s marriage certificate, which was dated 1946. The thing is, Heene was born in 1945.

After a bit of prying, her mother came clean. Her biological father was a Canadian soldier, Heene’s mother told her. The dashing young man was stationed in Ghent, Belgium during World War II. That’s where he met Heene’s mom.

The young couple developed feelings for each other, but the man was a soldier. Soon, he was stationed somewhere far away. The relationship ended, leaving Heene with a baby daughter.

She married the man who Heene would call her father, and he fulfilled the role admirably, and with love. He had a son and a daughter, who, while technically Heene’s half-siblings, were simply brother and sister to her.

But somewhere in the back of her mind, Heene always wondered who that mysterious soldier was. Could she have another family out there somewhere, maybe in Canada?

When she got into her seventies, Heene decided to do some more digging.

As a little girl, Heene found a box full of pictures of Canadian soldiers from the war era. Her mother had always told her that they were “uncles.” But Heene suspected one of them was her father.

Further investigation only unearthed a single clue: Heene believed her father’s first name was Herbert. She shared a few of the photographs and the name on social media. Then she waited.

The online response was overwhelming. Facebook users shared her post more than 114,000 times. Then Reddit picked it up, and it reached thousands more people, all over the world.

A retired Canadian Artillery sergeant named Gary Menten felt compelled to help when he saw the post.

“We have an expression that says, “Once a gunner, always a gunner,'” he told CBC News. “So this is very important to us.”

He sent the photographs to the Canadian national Library and Archives, asking for help with identification. They couldn’t name the man in the picture, but they could confirm that he was a sergeant in the Royal Canadian Artillery during the war years.

Finally, a family in Vancouver, Canada found Heene’s photographs online. They were sure they recognized their deceased grandfather, who served in the Canadian military during the Second World War.

His name? Herbert Louis Hellyer.

Heene had found her other family.

The entire process, beginning from the first Facebook post with the pictures, took less than two weeks.

Hellyer married and had five children before going off to war in 1939. Of that generation, only Hellyer’s son and two daughters survived to learn of Heene’s existence.

Thelma Janes, one of Hellyer’s Canadian daughters, was shocked and thrilled to learn of her half sister.

“I’m 79, and at 79 to find out you have a 71-year-old sister,” she told CBC News. “To think, all these years and we didn’t even know about her. I’m getting tears now just thinking about it.”

For Heene’s part, she finally feels a sense of completeness that had been missing her whole life.

“I have the piece that I was looking for,” she said. “Now I can close it.”

Hellyer’s children—on both sides of the Atlantic—plan to meet soon.

“I just want to chit chat with her and try and get friends with her,” Janes said.

Heene will also meet a grand-niece, Kristy Demidoff, who was the one to discover the Facebook post in the first place. When she saw the pictures of her grandfather online, she went through her mother’s old photo albums. Sure enough, she found an identical picture to the one that Heene had posted.

“It’s amazing, truly amazing,” Demidoff said. “This is the only picture our family has of him.”

Hellyer’s children and grandchildren aren’t upset about his war-time affair across the sea. They’re just glad to finally meet a missing member of their family.

“I’m an elderly woman,” Janes said. “I know what went on in the war, and it’s to be expected. That part doesn’t get me in the slightest. The part that we never knew about each other gets me.”