Online, she called herself "Prairie Girl" and "Canadiansweetie."

He was "redneckdriller."

Photographs posted on social media websites show a hugging couple along with three smiling children and a new baby. There's no hint of the horror that came this week when five of the six died in a murder-suicide in Tisdale, Sask.

But the family of Latasha Gosling say her boyfriend, oil rig worker Steve O'Shaughnessy, had been controlling and jealous.

And one friend says Gosling broke up with the man shortly before he turned deadly.

"She was the one who called it off," says Amanda Henderson. "Steve had an affair and cheated on her with a co-worker."

Henderson, a mother of four who lives in Gate City, Va., says she bonded with Gosling after they met two years ago through a Facebook group for separated and divorced parents.

Gosling, who separated from her husband and started living with O'Shaughnessy in a Tisdale trailer park, had founded the group. She and Henderson chatted online almost every day.

On Monday, Henderson said Gosling told her she had split up with O'Shaughnessy. She seemed calm about it and said she was going to take her time deciding where she and her children were going to live next.

After a few days of not hearing from Gosling, Henderson heard about the killings on Facebook and thought it must be some kind of cruel joke.

Mounties found the bodies of Gosling, 27, and her three children -- Jenika 8, Landen, 7, and Janayah, 4 -- early Wednesday in their mobile home.

After the killings, O'Shaughnessy, 23, took the couple's six-month-old baby girl from the trailer, drove 130 kilometres to Prince Albert and killed himself in a home there. The baby was found unharmed.

Disturbing details later emerged about how O'Shaughnessy had snapped photos of his victims' bodies and sent copies to the cellphone of Gosling's husband, the biological father of the three older children. Relatives say it was the day before the man's birthday and the photos were sent as a "birthday gift."

O'Shaughnessy's family says he suffered from mental health problems, but he had no history of violence.

Photos on Instagram show him mugging with the three children, pushing one on a bike and giving another a piggyback ride.

"I love you to pieces Dad!" said a card attached to a bag of candy in one photo tagged "#fathersday."

The kids called O'Shaughnessy "Dad" for awhile, Henderson said, but they stopped after their biological father started visiting them more regularly. Gosling's cousin, Tim Funk, said O'Shaughnessy didn't like the other man coming around.

Photos show O'Shaughnessy with a large tattoo on his arm of an oil rig. They also show him at work in a hard hat, hunting for deer and growing a beard.

In between pictures of homemade cookies and her children, Gosling proudly shows off a promise ring O'Shaughnessy gave her two years ago.

A Facebook memorial page shows Jenika, an aspiring child model, posing with flowers in her hair. Landen stands proudly with medals around his neck in a martial arts outfit. Janayah, a redhead, stands with friends in a gymnastics class.

In October, O'Shaughnessy is seen cradling his newborn girl, his eyes brimming with tears.

"This is the reason I work my ass off," O'Shaughnessy posted with the picture of the baby, the only one that survived.