Maggie Atkinson said that her mother remains on life support and family members must wait to see how she fares in the days ahead.
"She's on life support and we won't really know until the end of the week how things are. I mean, it's very critical and it's very touch and go at this point," she told CBC News on Monday afternoon.
She said that her family is thankful for the support they have received from the public.
Another daughter, Julie Atkinson, said she flew to Toronto from Vancouver Island after learning what had happened to her mother.
"I'm just really happy that my mom is in the hospital and they are giving her the best care possible," she said Monday.
"And all our prayers are with her and we really hope that she has a recovery, we don't know what’s going to happen."
The fire broke out at Irene Atkinson's house around 7 p.m. on Saturday.
"She was trying to get out the front door and I’m so upset that she couldn’t make it," Julie Atkinson said.
News of the fire spread quickly on Sunday. Many of Atkinson's friends, along with Toronto Mayor Rob Ford and Premier Kathleen Wynne, issued messages wishing her a speedy recovery.
"She's one of the strongest fighters I’ve ever met but she’s fighting for her own life right now," Wynne said Monday morning in the Ontario legislature.