A 35-year-old woman who was stabbed to death in a William Avenue rooming house was pregnant when she died, according to her neighbour.

Cynthia Marie French was rushed to hospital in critical condition around 6 p.m. Tuesday. She later died.

Another woman, who is 36, was also stabbed and sent to hospital as critical, but her condition was later upgraded to stable.

Candice Nora Nepinak, 31, and Vanessa Louise Nepinak, 35, are both charged with second-degree murder and attempted murder in the city's first homicide of 2016, police announced Wednesday.

Neighbour Ernest Chartrand said French was pregnant and due to give birth soon, but police would not confirm if she was pregnant citing privacy concerns.

"She was a really good person," he said. "She was very nice and a sweet girl. She was very polite to everybody and very friendly."

Chartrand said French also had at least two other children.

2 sets of sisters involved

The mother of Tanya Nepinak, a Winnipeg woman who disappeared five years ago, says she's shaken to learn that two of her other daughters now face murder charges in connection with the stabbings.

Joyce Nepinak confirmed the two accused are her daughters. They are also the sisters of Tanya Nepinak, whose disappearance in 2011 helped prompt calls for a national inquiry into missing and murdered indigenous women.

Nepinak said she was shocked when a friend called her on Wednesday morning to say the two sisters had been arrested.

"I started screaming and crying," she said. "I'm still shaky."

Tanya Nepinak's sisters charged with murder in Winnipeg rooming house stabbing2:05

According to police, the victims were also sisters. They arrived home Tuesday afternoon to discover Vanessa Nepinak in French's room, police said.

Vanessa was forced out of the home but returned with her sister an hour later and attacked French and the other woman, police added.

French's sister escaped and made her way to a payphone where she contacted police. The Nepinaks then went after her at the payphone and attacked her again, according to police.

Vanessa was arrested at that scene while Candice was arrested a short time later in the 400 block of Pacific Avenue, police said.

A neighbour of the rooming house told CBC News there were several police officers at the house Tuesday evening but she didn't think much of it, saying it's not unusual for that place.

Police confirmed they are very familiar with the house and noted blood, which could be seen on the front door handle, was old and from another incident.

Missing since September 2011

Tanya Nepinak was 31 years old when she was last seen leaving her Winnipeg home to walk to a pizza restaurant several blocks away in September 2011.

Convicted killer Shawn Lamb was charged in connection with her death in 2012, but those charges were later stayed.

Nepinak's body has never been found, and her family has been searching for answers over the years.

Joyce Nepinak said news of Candice and Vanessa being charged with murder has taken a toll on her family, which continues to struggle with Tanya's disappearance.

"It's really hard on me, really hard," she said.

She said Candice and Vanessa were very close and protective of each other, adding that both daughters were known to get into fights with other women "for nothing."

"Candice has been doing time; she was a very angry person," Nepinak said of her daughter. "I think she got herself angrier and angrier instead of talking to someone that she was angry about everything."

Nepinak said she does not know who the victim was or why her daughters were at the William Avenue rooming house on Tuesday night.

"I'm sorry for what happened to that woman … it really hurts me for what happened," she said.

"It made me feel really bad. I'm still kind of shaken."

Nepinak said she last saw Candice three days ago, while she speaks with Vanessa on the phone every day. However, she said she hasn't been able to speak to either daughter since they were arrested.

She said her husband died of cancer in March 2014 and her brother died two days before that, so the arrests have been hard on her and her family.

"Everybody is taking it hard," she said. "With my daughter's disappearance and my husband and my brother, everybody is taking it hard."

Nepinak sisters in trouble before

Both of the Nepinak sisters charged in French's death have criminal records. 

Candice Nepinak has a list of dozens of prior convictions, including 37 for failing to comply with court orders and theft, assault, robbery, possessing a weapon and forcible entry. 

Vanessa Nepinak has eight convictions, which include communicating for the purpose of prostitution, public mischief and theft. 

Both are expected to make their first court appearance to face the new charges Thursday. 

With files from the CBC's Nelly Gonzalez