Lulonda Lynn Flett, 41, had faced five counts of second-degree murder and three counts of attempted murder in connection to the blaze in the Point Douglas neighbourhood.
The plea is part of a deal with the Crown to avoid a long trial. In addition to five counts of manslaughter, Flett also pleaded guilty to one count of arson.
Court of Queen's Bench Justice Brenda Keyser asked Flett, who was sniffling a bit throughout the hearing, if she clearly understood the charges.
"You hesitated a bit. Are you certain this took place?" Keyser asked Flett in court.
"Yes," Flett answered.
"You appreciate you will go to jail for long period of time?" the judge asked.
"Yes," Flett said.
"Anything you want to say?" Keyser asked.
"No," Flett replied.
Her lawyer, Darren Sawchuk, said Flett did not intend to kill anyone.
"I think once the facts are laid out before the court, when we return [for sentencing], you'll have a better understanding of the lack of intent in this case and the other circumstances that make manslaughter the appropriate charge," Sawchuk said outside court.
Maximum penalty is life in prison
Flett faces a maximum penalty of life in prison. A sentencing hearing is set for March 21, 2013.
Sawchuk would not say what sentence he will seek, nor would he discuss details of what happened until the sentencing hearing takes place.
The fire at 288 Austin St. broke out in the early morning of July 16, 2011.
There were eight people in the home at the time, including Flett's sister-in-law, Lynette Harper, who escaped unharmed.
The week before the fire, court records show Flett had been ordered by the courts to stay away from Harper. Flett had been handed a conditional sentence on assault charges after pleading guilty to participating with another woman in a 2009 attack on Harper.
Those who died in the blaze were:
- Norman Darius Anderson, 22.
- Maureen Claire Harper, 54.
- Kenneth Bradley Monkman, 49.
- Dean James Stranden, 44.
- Robert Curtis Laforte, 56.
Fire officials have said the blaze likely started near the front entrance, possibly on the veranda, blocking an obvious escape route. The front of the structure was engulfed when firefighters arrived.
Court was told a Gladue report — a pre-sentence assessment for aboriginal offenders — will be prepared before the March date.
Gladue reports are based on a Supreme Court of Canada ruling that said judges should take an aboriginal offender's background into account for sentencing.
Flett is originally from a remote First Nation, Sawchuk said.
"She's from a remote northern community and she doesn't have much of a history with the courts, so this whole event today is in some ways probably a relief to her that we're moving the matter forward," he said.
"It's a tragic case. It's a terrible case and my client has accepted responsibility for the role she played in it."
Lyle Duhaime, who lived in the rooming house before and after the blaze, said he knew three of the five people who died.
"It always hurts, especially when people aren't ready to die yet," Duhaime told CBC News.
"They're still alive … it wasn't their time, eh? It didn't happen naturally."
Duhaime said if he had been living in the house at the time of the fire, he likely would have died as well.