The tragedy was felt by people across Canada and prompted a conversation about postpartum mental health that continues today.
Those who work in the perinatal and mental health fields say the case has changed the stigma around postpartum depression and has prompted more people to ask for help.
"It really demonstrated that mental health challenges can happen to anyone," Erin Bockstael of the Women's Health Clinic in Winnipeg told CBC News on Thursday.
Gibson's two-year-old daughter, Anna, and three-month-old son, Nicholas, were found close to death in the bathtub of the family home on July 24, 2013. They later died in hospital.
The body of Gibson, 32, was recovered from the Red River on July 28, 2013.
Winnipeg police later declared the deaths as a homicide/suicide. The cause of death in all three cases was determined to be drowning.
Manitoba's chief medical examiner confirmed that Gibson had been diagnosed with postpartum depression.
Dr. Thambirajah Balachandra decided not to call an inquest, but called on health-care providers to actively educate new mothers about postpartum mental health issues.
Calls doubled in past year
The Mood Disorders Association of Manitoba says it has received more calls about postpartum mental health in the year following the Gibson deaths.
"I'd say it's at least probably doubled since the tragedy, for people seeking help," said Adam Milne, an outreach manager and volunteer co-ordinator with the association.
Milne said it's not just mothers who are calling for help — fathers, grandparents and other family members have been contacting the association to learn more about perinatal mental health.
In fact, he said 60 per cent of the calls are coming from fathers, so the association has started offering resources for them.
"It was very surprising in the beginning, but made a lot of sense as we came through," Milne said.
"People were coming in and speaking to me about it, and it's them that are trying to help because they are trying to support the mom."
More programs being offered
As well, there has been an increase in programs being offered to help families, and Milne said people are taking advantage of that.
"I think people know that they can call here to talk about it, more so than any year previous," he said.
"I think that it's in the forefront of people's minds when they're having babies that it's important that they reach out and they develop their support network early."
The Mood Disorders Association launched a "postpartum warmline" for new parents last fall, while the Postpartum Depression Association of Manitoba launched a "one-stop" information website earlier this year.
The Women's Health Clinic is offering prenatal classes focused on mental health, said Bockstael.
"Our prenatal classes have been consistently full, people have really enjoyed the workshops, and we're finding that the word's really getting out about some of these programs," she said.